Wladimir Klitschko has called on "the entire world" to help stop the ongoing crisis in Ukraine, amid Russia's invasion of the country.

Russia invaded Ukraine on Thursday after weeks of rising political tension. That conflict escalated on Friday and into Saturday, with fighting now reported to have reached the capital, Kyiv.

Wladimir, a two-time heavyweight world champion, and his older brother Vitali, who is the mayor of Kyiv, have both pledged to take up arms to help defend the city and their country.

In a video posted to his official Twitter account on Saturday, Wladimir Klitschko spoke powerfully of the need for more action from other nations.

Heavy sanctions have been placed on Russia by the United States, the European Union and the United Kingdom, though there is no sign of a ceasefire. 

Russian officials have offered to hold peace talks with their Ukrainian counterparts, though only on the condition that Ukraine's army surrenders.

"I'm addressing the entire world, to stop this war that Russia has started," Wladimir Klitschko said in the video. 

"Just today, civilians were shot by the rockets with special operations surveillance getting killed(*), and it's happening in the heart of Europe.

"There's no time to wait, because it's going to bleed into a humanitarian catastrophe.

"You need to act now to stop Russian aggression, with anything you can have now. In an hour, or by tomorrow, it's going to be too late. Please, get into action now. Don't wait, act now, stop this war."

Multiple sportspeople and organisations have called for the end of the conflict, with Russia having been stripped of the Champions League final – initially due to be held in St Petersburg – and the Formula One Russian Grand Prix.

(*) Wladimir Klitschko's claim could not been verified at the time of publication.

Ukrainian tennis star Elina Svitolina is "really praying" for her country after Russia invaded on Thursday, following weeks of rising political tensions in the region.

The conflict escalated further on Friday, with the fighting reaching the capital city of Kyiv.

Several high profile sports figures have publicly expressed their opposition to war, including Russia's Andrey Rublev who wrote "no war please" on a camera lens at the Dubai Tennis Championships, joining compatriot Daniil Medvedev in calling for peace.

Svitolina - who is ranked 15th in the world - has said she is praying for peace and trying to keep in contact with her family back in Ukraine.

"I'm shocked at this terrible nightmare," Svitolina told Sky Sports News. "I'm really praying every single minute for my family, for my friends, for all people in Ukraine and around the world for safety, for peace.

"Considering what people are going through in Ukraine and what my family are going through while being in Ukraine and friends, I try to keep in contact with them to see what's happening there.

"I'm very safe compared to them. To be honest with you, I'm only thinking about them and for me, it's a very stressful time because I cannot do anything. I cannot really help them. I wish I could help them. It's extremely tough mentally for me. I cannot imagine what they are going through. I'm just praying.

"It's a horrible situation for the people in Ukraine, what they have to go through without sleepless nights, without food and electricity so that's horrible. For me, it's heartbreaking to hear this.

"The war is something we have to stop and it's something better than anything else. What is happening is very tough for me to imagine."

Ex-England star Jason Leonard has congratulated Ben Youngs as he gets set to become the nation's most-capped player in men's international rugby ahead in their Six Nations clash with Wales.

The scrum-half will start from the bench for Eddie Jones' side at Twickenham, with Harry Randall favoured in the initial XV, but will win his 115th cap for his country when he enters the fray.

That will take him past former World Cup winner Leonard, with whom he jointly sits on 114 caps at the top of the leaderboard.

The former Harlequins favourite took to social media ahead of the match to pay tribute to Youngs' achievement.

"All the best Ben Youngs," the former prop wrote on Twitter. "I know Twickenham will raise the roof for your 115th cap, as I will be one of them!

"I couldn't want for a better individual to pass the record [to] as you are an absolute credit to the game. [It's been] an absolute honour to have held the record for so long."

Youngs will remain shy of Leonard's total international cap record for a few more games at least, however, given that the latter has played more games for the British and Irish Lions.

Both remain well shy of Wales stalwart Alun Wyn Jones' all-time men's record, with the lock having picked up 161 caps to date - 149 for Wales and a dozen for the Lions.

LeBron James has quashed suggestions he is set to leave the Los Angeles Lakers, while repeating that he hopes to continue his career long enough to eventually play alongside his son.

The 37-year-old, one of the NBA's most successful superstars of the twenty-first century, joined the Lakers in 2018, leading them to a 2020 championship - the fourth of his prolific career.

Yet, following comments around the league's All-Star game over wanting to play alongside his son Bronny, speculation had run rife that James could leave the Lakers to finish his career with another franchise.

Speaking after the 105-102 defeat to the Los Angeles Clippers on Friday though, James sought to shut down discussion, saying he is committed to the franchise through the end of his contract and beyond.

"This is a franchise I see myself being with. I'm here. I'm here," he said. "I see myself being with the purple and gold as long as I can play."

James' current deal has one more season to run, though he is eligible to pen a two-year extension later this year, while high schooler Bronny would not be available to be drafted until the 2024-25 campaign.

"I also have a goal that, if it's possible - I don't even know if it's possible - that if I can play with my son, I would love to do that," James added.

"Is that, like, something that any man shouldn't want that in life? That's like the coolest thing that could possibly happen. That doesn't mean I don't want to be with this franchise."

James - who top scored with 21 points in the loss to the Clippers, as well as managing 11 rebounds - also admitted he remains frustrated by the lack of game time he has shared with Anthony Davis and Russell Westbrook this season, with the trio often split by injury.

"I do wish that we were just playing better basketball and between me, AD and Russ on the floor at the same time," James said. "That's the biggest disappointment so far, that us three, because we all wanted to see this work. We just haven't been on the floor."

Dan Biggar says he will not have to plan his pre-match speech when Wales face England in the Six Nations, adding that the emotion should prove enough for his side.

The Northampton fly-half will skipper Wayne Pivac's side at Twickenham as they look to give their Championship hopes a shot in the arm.

Wales have not won at the home of English rugby since 2015, having lost on their last five visits – and Biggar admits that his side should need no motivation to deliver.

"Sometimes very little is needed to be said," he stated. "It's very much down to the individual.

"I'd like to think that in a pivotal weekend in the Six Nations against England at Twickenham there won't be too much needed [to be] said from an emotional level to get us going.

"At some point you have to roll your sleeves up. Do we want to be enjoying a beer after putting everything in and enjoying the result?

"Or do we want to feel that we haven't given it our all and are really quite disappointed with how we played and let the country down?"

Biggar admitted that Wales need to ensure they make a sharp start, having historically sunk to defeat against England after falling behind early on.

"We need to make sure that when we go away to tough places, like the Aviva, like Twickenham, we start well," he added. "It's important we don't give them a start.

"It's such a difficult task. Even if you get yourself back in the game, one more score for England takes you out. They've got some serious strength in depth and they're a very good side."

Rafael Nadal continued his tremendous form as he beat Daniil Medvedev in straight sets to set up a final with Cameron Norrie at the Mexican Open.

Nadal found this victory over Medvedev to be more straightforward than his remarkable five-set comeback win in last month's Australian Open final between the pair, winning 6-3 6-3 in Acapulco.

The victory means the Spaniard moves on to 14-0 for the new season, which is already his best ever start to a year.

The soon-to-be world number one Medvedev at least made him work for it in the second set and earned 11 break points across two consecutive service games, but a determined Nadal rescued all 11 of them, including seven in a marathon nine-deuce game at 6-3 3-2.

"I played some amazing points on the break points," said Nadal following the win. "The second set was very emotional. Daniil was playing very aggressive – drop shots, winners. It was a very difficult set. I feel lucky to win that set because he had a lot of chances."

He will now face sixth seed Norrie on Sunday, who also came through his semi-final against third seed Stefanos Tsitsipas in straight sets, 6-4 6-4.

The Brit – who won the Delray Beach Open last week – was particularly impressive on his serve, making 92 per cent of his first serves in the opening set. That dropped to 57 per cent in the second, but the quality of his baseline shots took him to victory.

Meanwhile at the Chile Open, local wildcard Alejandro Tabilo continued his good run, having already knocked out top seed Cristian Garin, with a 6-1 6-4 win over sixth seed Miomir Kecmanovic.

Tabilo will face Pedro Martinez in the semi-finals after the Spaniard won 6-2 6-2 over Yannick Hanfmann.

Sebastian Baez will meet second seed Albert Ramos Vinolas in the other semi-final after he got past Facundo Bagnis 7-5 6-2.

James Harden scored 27 points with 13 assists on his Philadelphia 76ers debut and formed a strong partnership with Joel Embiid in a 133-102 win over the Minnesota Timberwolves on Friday.

Harden, who crossed from the Brooklyn Nets in an NBA Trade Deadline move earlier this month, almost registered a debut triple-double, with eight rebounds.

Embiid has been in irrepressible form this season, although there had been some concern Harden's arrival may blunt some of his offensive impact, but the center contributed 34 points, 10 rebounds and three assists.

The new-look 76ers had immediate cohesion, scoring 65 points in the first half, before a 41-point final quarter with Tyrese Maxey finishing with 28 points while Harden also drained five three-pointers, shooting seven-of-12 from the field.

The 76ers recorded a season-high 19 three-pointers for the game, with head coach Doc Rivers admitting "that was pretty good" when asked post-game if Harden's debut could have gone any better.

Lakers fall to Clippers again

Terance Mann led the way with 19 points and 10 rebounds as the Los Angeles Clippers won a tight game with the Los Angeles Lakers 105-102, the sixth time in a row they have beaten their local rivals.

LeBron James top scored with 21 but was unable to stop the Clippers from taking charge in the closing moments, with Amir Coffey adding 12 of his 14 points for the night in the fourth quarter.

The San Antonio Spurs edged the Washington Wizards 157-153 in double over-time, with both teams setting season-highs in scoring. Spurs guard Dejounte Murray recorded a triple-double, although he missed potential winning shots in both regulation and the first over-time.

RJ Barrett scored 46 points including six three-pointers but the New York Knicks went down 115-110 to the Miami Heat, while Donovan Mitchell scored 33 points and Rudy Gobert had a double-double (14 points and 17 rebounds) as the Utah Jazz beat Luka Doncic's Dallas Mavericks 114-109.

Suns streak halted

The table-topping Phoenix Suns' eight-game winning streak came to an end, going down 117-102 to the lowly New Orleans Pelicans. Devin Booker top scored with 30 points for the Suns, who were without injured veteran guard Chris Paul. CJ McCollum scored 32 points for the Pels as he continues to thrive following his trade.

Sloane Stephens fought back from a set down to reach her first hard court semi-finals since 2018 as she defeated Daria Saville at the WTA Abierto Zapopan on Friday.

The 2017 US Open champion triumphed in two hours and 29 minutes over the Australian, winning 4-6 6-3 6-2 in Guadalajara.

Stephens, who will play Russian Anna Kalinskaya in the last four, had not reached a hard court semi since the 2018 WTA Finals.

But the American was forced to do it the hard way after losing the first set, saving nine of 13 break points across the match, with her ability to win second serve points proving key.

Colombian fourth seed Camila Osorio was bundled out in 80 minutes by Kalinskaya 6-4 6-1.

There was also a straight-sets win for Marie Bouzkova after she defeated third seed Sara Sorribes Tormo 6-4 6-1.

She will face Wang Qiang in the last eight, who proved too good for Slovakian Anna Karolina Schmiedlova 6-2 6-3.

Joel Embiid could not hide his smile in the fourth quarter of the Philadelphia 76ers' 133-102 win over the Minnesota Timberwolves as his partnership with debutant James Harden thrived.

Harden was making his 76ers debut after his NBA Trade Deadline move from the Brooklyn Nets, with the 2018 MVP scoring 27 points including five three-pointers along with eight rebounds and 12 assists.

Embiid's influence remained as strong as ever, finishing with a game-high 34 points along with 10 rebounds and three assists.

The 76ers piled on the points showing Embiid and Harden had struck immediate cohesion with 65 first-half points, while they added another 41 in the fourth quarter.

"You should’ve seen my face every single time especially in the fourth," Embiid told NBC Sports after the game. "The first three quarters obviously making plays for all of us.

"That was probably the most wide open I've ever been in my career. I had a lot of easy baskets.

"I used to have to work for everything but I the fourth quarter the shot-making ability and shot creation, you should’ve seen my face.

"I've never had this. Nothing close to it. Hopefully it continues. We didn’t even play our best. I think we can be way better than that."

The combination quelled fears that Harden's arrival may stifle Embiid's offensive impact, which has him among this season's MVP candidates.

Instead, Harden's influence enabled others to make strong impacts, including Tyrese Maxey who finished with 28 points, while the Sixers managed a season-high 19 three-pointers.

"Easy shot after easy shot. You've just got to be winning shooters. That's what we were tonight," Embiid added.

"[Harden] attracts a lot of attention. When you've two guys on the floor who do that, me and him, it becomes a little easier for everybody else. it's on everyone else to just make shots."

Hometown hero Daniel Berger opened up a three-stroke lead at the halfway mark of the Honda Classic in Florida after carding six birdies on Friday.

Berger, who is ranked 20th in the world, backed up his opening day five-under 65 with a repeat score, highlighted by a 38-foot birdie putt on the par-three seventh hole, to be 10-under at Palm Beach Gardens.

The Florida native leads by three shots from Chris Kirk and first day leader Kurt Kitayama, the latter carding a one-under-69 to slip from the summit.

“Just one of those days when I kept the momentum going,” Berger told reporters. “I hit a lot of quality shots, even though they don't look like they're five feet from the hole, or 10 feet from the hole.

“I know that they're so difficult, that to hit it to 20 feet is a good shot. And that's the challenge for this golf course is the pins are tucked, the greens are firm, wind's up, so you have to be really on point with where you're going to miss.”

Mark Hubbard surged up the leaderboard into a tie for fourth alongside Canadian Adam Svensson with the pair carding rounds of 64 and 65 respectively to be six-under overall.

Pre-tournament favourite Louis Ousthuizen produced a strong round to avoid the cut, after his opening day five-over-75.

The South African is even after two rounds, behind Berger by 10 strokes, but managed six birdies on his back nine to stay in contention after a double bogey on the 11th hole seemed to condemn him.

Four-time major winner Brooks Koepka is among a large group alongside Oosthuizen that are even after two rounds with the American carding a two-over-72.

Padraig Harrington, Brian Harman, Charl Schwartzel and last week's Genesis Invitational winner Joaquin Niemann were among those to miss the cut.

Russia's Andrey Rublev wrote "no war please" on a camera lens as he joined compatriot Daniil Medvedev in calling for peace.

Rublev beat Hubert Hurkacz 3-6 7-5 7-6 (7-5) on Friday to progress to the final of the Dubai Tennis Championships.

After confirming his place in a showdown with Jiri Vesely, the 24-year-old world number seven took a pen and scribed "no to war" on the lens of a television camera.

Vesely later wrote 'no war' on a camera lens after defeating Denis Shapovalov to book his place in the final.

It is not uncommon for players to write messages on camera lenses, but a plea for peace was an emotive move from Rublev.

On Thursday, Russia invaded neighbouring Ukraine following weeks of rising political tensions. The conflict escalated further still on Friday, with reports of fighting within the capital city of Kyiv.

Rublev's actions came after Medvedev – who will succeed Novak Djokovic as world number one next week – said he wanted to "promote peace".

Medvedev has reached the final four of the Mexican Open in Acapulco.

Rublev had previously expressed his wish for peace in a news conference at the Dubai event.

"In these moments you realise that my match is not important," Rublev said, with a video clip shared to his official Instagram account.

"It's not about my match, how it affects me. What's happening is much more terrible.

"You realise how important it is to have peace in the world and to respect each other no matter what, to be united. 

"We should take care of our Earth and of each other. This is the most important thing."

Anett Kontaveit defeated Jelena Ostapenko in straight sets, while Iga Swiatek overcame Maria Sakkari to secure her place in the Qatar Ladies Open final.

Swiatek advanced to the Doha showpiece for the first time after managing her first win over Sakkari in four attempts with a 6-4 6-3 triumph on Friday.

The Pole was in imperious form as she delivered 20 winners to overcome sixth seed Sakkari in an hour and 28 minutes, collecting her seventh top-10 win and second straight such win after defeating Aryna Sabalenka in the quarter-finals.

The seventh seed will now meet Kontaveit, who continued her impressive streak with a 6-1 6-4 win over Ostapenko in just 68 minutes.

Ostapenko headed into the clash on a career-best nine-match winning run, but succumbed to her fourth loss in five meetings with the fourth seed in Qatar.

Ostapenko did have back-to-back break points at 5-5 in the final set, but Kontaveit managed to hold on for victory.

"She can outplay anyone, and then she might not find the consistency sometimes, so you have to be ready for that," Kontaveit said of Ostapenko.

"I was trying to play a consistent match and just do my best on my serve and hold on to it, especially in the second set when I was a break up.

"Sometimes when she's on fire, her returns are unplayable and it's just very difficult.

"But I kept repeating to myself, 'I'm really good at serving it out, I'm really good at serving it out,' and eventually managed to do that.

"How you approach the match, how you're approaching the service games, I think if you're trying to be aggressive [...] that has a lot of effect on the serve."

It will be the seventh final that Kontaveit has contested since last August, converting those appearances into five titles so far. Kontaveit and Swiatek share a pair of wins apiece in previous clashes.