Kylian Mbappe pledged France will return to the biggest stage after his World Cup final hat-trick was not enough to deny Lionel Messi and Argentina glory in Qatar.

Mbappe's remarkable treble – just the second to be scored in a men's World Cup final – ensured France forced a penalty shoot-out at the end of a back-and-forth 3-3 draw at Lusail Stadium.

He then converted the first penalty of the shoot-out, but was denied a second World Cup triumph as Kingsley Coman and Aurelien Tchouameni failed to score, handing the Albiceleste their third title.

Mbappe, who turns 24 on Tuesday, was defiant in his first social media post after Les Bleus' defeat on Monday, writing on Instagram: "We will return".

Three-time World Cup winner Pele was among those to respond to Mbappe's post, simply writing: "Merci".

The Paris Saint-Germain forward's tally of four goals in World Cup finals is unmatched by any player, while he is one of just five men to net in two showpiece games at the tournament – alongside Vava, Pele, Paul Breitner and Zinedine Zidane.

Former France attacker Louis Saha hailed Mbappe's performance when speaking to Sky Sports on Monday, describing it as unprecedented for a player of his age.

"It was stratospheric, it's an unbelievable achievement for a young guy like him to do that on that stage," Saha said.

"Everyone was looking for him, even Argentina were looking to defend him and doing everything to stop him. It was not possible. 

"On the big stage, with all the pressure on his shoulders, he managed to do this. 

"It's sad for him because for such a young age, he would have written a unique story. Nobody has done something like this.

"With all respect to other players, legends of the game, this guy's performance to maintain France's dream… the quality of his attitude through the tournament, it was absolutely breathtaking."