Press, 31, who scored in the USA's World Cup semi-final win against England last year, joins United following a spell with Utah Royals.

Heath and Press have played 168 and 138 times for their country respectively.

Heath said: "Manchester United is an exceptional club and I'm thrilled to be joining them.

"I'm looking forward to the challenge of competing in England, playing with and against some of the best players in the world.

"I have big ambitions for this season and can't wait to get on the pitch with my new team and start this next chapter."

Press said: "I'm really excited to be joining Manchester United this season. I'm grateful to have the opportunity to play for such an elite club and beyond ready to get back on the field.

"I feel blessed to have the opportunity to continue to strive to be my best and to compete for trophies this year. I look forward to this new challenge and I can't wait to start training with the team."

United boss Stoney described Heath as an "outstanding player who brings a wealth of experience to the squad", adding: "She is extremely skilful and possesses so much quality on the ball; her speed and intelligence in one vs one situations will be a real asset that will push the team forward this season, and I can't wait to see her make her mark on the league."

On Press, who has scored 58 international goals, Stoney said: "Christen is a world-class player and we are thrilled to have her on board at the club.

"She has a proven record and her stats speak for themselves; she's a ruthless striker who scores so many different types of goals, and I know she can add some real quality to our squad."