Twenty-eight members of the U.S. national women's soccer team filed a federal gender discrimination lawsuit against the U.S. Soccer Federation on Friday morning.

In the complaint, which was filed in U.S. District Court in California, the players allege gender discrimination on a number of levels, from their salaries to the types of fields on which they play and their travel accommodations on the road.

"Despite the fact that these female and male players are called upon to perform the same job responsibilities on their teams and participate in international competitions for their single common employer, the USSF, the female players have been consistently paid less money than their male counterparts," the players write in the lawsuit, which was obtained by USA TODAY Sports.

"This is true even though their performance has been superior to that of the male players — with the female players, in contrast to male players, becoming world champions."

The players — including stars such as Carli Lloyd, Alex Morgan and Megan Rapinoe, among others — are also seeking class-action status, which means the lawsuit would represent all current and former members of the women's national team since Feb. 4, 2015.

The New York Times first reported the existence of the lawsuit Friday — which is also International Women's Day.

The lawsuit represents the continuation of a years-long fight for equal pay from women's soccer players. Four players filed a discrimination complaint with the U.S. Equal Employment Opportunity Commission in 2016 and were issued rights to sue early last month, according to the lawsuit.

The lawsuit also comes roughly three months before the team will set out to defend its World Cup crown, with its first match in France scheduled for June 11.

A spokesperson for U.S. Soccer did not immediately reply to an email from USA TODAY Sports seeking comment on the lawsuit.

In their complaint, the players claim that U.S. Soccer has "continually rejected WNT players’ requests for pay equal to the pay afforded to MNT players" and continued to employ a pay scale that is skewed in favor of men.

Among a number of specific examples listed in the lawsuit, the female players claim that women's national team players were given $15,000 apiece for making the 2015 World Cup roster, while men were given $55,000 apiece the previous year. The female players also claim that the men's national team earned $5.375 million in bonuses for its performance in the 2014 World Cup — a loss in the Round of 16 — while the women earned $1.725 million for winning the 2015 tournament.

The lawsuit also claims that "during the period relevant to this case, the WNT earned more in profit and/or revenue than the MNT."

Finances aside, the women's national team members argue that they receive unequal treatment in terms of travel accommodations and playing conditions. They claim they are required to play on artificial surfaces more frequently than the men's team, and receive charter flights to away games less frequently.

Contributing: Nate Scott

Contact Tom Schad at tschad@usatoday.com or on Twitter @Tom_Schad.