Megan Rapinoe and Alex Morgan said the US women's national team will appeal against defeat in their equal pay lawsuit on Monday, describing the judge's ruling in the case as "shocking".
In a widely unexpected decision on Friday, Judge Gary Klausner rejected the US women's claim of pay discrimination, finding in favour of the United States Soccer Federation.
Although the judge said claims of gender discrimination in areas such as travel, housing and medical support could proceed to trial, the equal pay part of the lawsuit - the central plank of the women's case - had been dismissed.
Speaking on ABC television's Good Morning America program on Monday, Rapinoe and Morgan voiced dismay at the outcome but pledged to fight on.
"We were just shocked," Morgan said. "This decision was out of left field for us. I think for both sides it was very unexpected. We will definitely be appealing and moving forward.
"If anyone knows anything about the heart of this team, we are fighters and we will continue to fight together for this."
In dismissing the equal pay claim, Judge Klausner said the case was unwarranted because there was evidence the women had previously turned down an offer in the Collective Bargaining Agreement negotiations to be paid along the lines of the US men's team.
However Rapinoe challenged that part of the judge's decision.
"The men's contract was never offered to us and certainly not the same amount of money," Rapinoe said.
"I think so many women can understand what this feeling is of going into a negotiation, knowing equal pay is not on the table, knowing anywhere close to your male counterparts is not even on the table."
Rapinoe also said the fact that the women had earned more than the US men during the period where pay discrimination was alleged was also misleading.
In the period in question, the women's team played 111 games and earned $24.5 million. The men played 87 games and made $18.5 million. The men's figure however would likely have been substantially higher had they qualified for the 2018 World Cup.
"If we were under the men's contract, we would be making three times more," Rapinoe said.
"So you can look at the total compensation. In that time that we've made just a little bit more, we've won two World Cups and we've won just about every single game that we've played in.
"So the rate of pay is just so different. It's just so frustrating."
The US women, who clinched back-to-back World Cup wins with victory at last year's finals in France, had been seeking back pay of $66 million under the US Equal Pay Act.