The United States women's football team have filed an appeal against a decision to dismiss their bid for equal pay.
A judge last week rejected the players' claims they were underpaid compared to the US men's side.
The lawsuit was filed by 28 women's national team players last year against the US Soccer Federation (USSF) and they had been seeking $66m (£52.8m) in damages under the Equal Pay Act.
Spokeswoman Molly Levinson confirmed the appeal was submitted on Friday.
"Equal pay means paying women players the same rate for winning a game as men get paid," she said.
"The argument that women are paid enough if they make close to the same amount as men while winning more than twice as often is not equal pay."
Giving its ruling, the court said: "The women's team has been paid more on both a cumulative and an average per-game basis than the men's team over the class period."
However, federal judge Gary Klausner allowed the players' case for unfair treatment in travel, housing and medical support to go to trial, which is set for 16 June in Los Angeles.
The US team won the Women's World Cup last summer for their fourth title overall. They have also won five Olympic gold medals.
The US men's team reached the World Cup quarter-finals in 2002, while their best finish was third place in the inaugural tournament in 1930.
After the equal pay claim was dismissed, striker Megan Rapinoe, who won the Golden Ball and Golden Boot at last year's World Cup, tweeted: "We will never stop fighting for equality."
Joe Biden, the presumptive Democratic nominee for US president in this year's election, said: "To US Soccer: equal pay, now. Or else when I'm president, you can go elsewhere for World Cup funding."
The USSF said it wanted to work with the team to "chart a positive path forward to grow the game both here at home and around the world".
Former USSF president Carlos Cordeiro resigned in March after lawyers for US football's governing body made submissions as part of the lawsuit in which it was claimed that the job of a male footballer on the national team "requires a higher level of skill based on speed and strength" than their female counterparts.
Before they played Japan in the SheBelieves Cup on 12 March, the US players turned their tops inside out during the warm-up to hide their badges, leaving only the four stars which represent their World Cup successes on show.
The women's case had been publicly supported by male players, and in February the US men's team issued a statement criticising the governing body, saying that "the federation continues to discriminate against the women in their wages and working conditions".