"Important to remember that these issues are/can be collectively bargained."
US Presidential candidate Hillary Clinton said: "Wouldn't want to face these women on the field or in the courtroom. Every woman deserves equal pay."
The complaint against the US Soccer Federation was filed with the Equal Employment Opportunity Commission on Thursday morning.
One of the lawyers representing the players, Jeffrey Kessler, said the women's game generated more income for US Soccer than the men's and it was time to address the "discriminatory and unfair treatment'' they have endured for years.
The five players were acting on behalf of all the players, he said.