Emma Hayes saluted the efficiency and clinical edge demonstrated by USA Women, who enjoyed a commanding 4-0 victory over South Korea in her first match in charge.

The former Chelsea boss made a winning start with the Stars and Stripes, as Mallory Swanson and Tierna Davidson scored a brace apiece at Dick's Sporting Goods Park.

Hayes departed Chelsea last month after a glittering 12-year spell, which culminated in her guiding the Blues to a fifth successive Women's Super League title.

The 47-year-old officially started her new job when she linked up with the US Women's national team in Colorado this week, and is already seeing strides being made.

"You can see we're building something," Hayes told ESPN. "There's lots of work to do. There are lots of holes in our play, no question, but it was a good start.

"I get to enjoy these amazing players. I just feel re-energised, and I want to coach this group, and they want to be coached.

"In terms of what I asked from the group, what we prepared for, the execution of that, we've made steps in the right direction.

"I felt for the first 30 minutes, it was technical execution where we struggled. We scored in our first three chances, so we were efficient, we were clinical."