"Ultimately we need to grow the women's game," Kirby told reporters on Friday. "That's the biggest issue, it always has been. Then you can talk about equal pay and everything else.
"We need to win the World Cup to have a leg to stand on in those situations. But if we keep improving the game on and off the pitch, those arguments can start to creep in.
"We're doing the same job as the men but I understand that we're not filling out stadiums -- that makes it difficult to have that argument. As the women's game improves and progresses, then they're the conversations we can start to have."
The U.S. women's national soccer team, who are the defending champions and ranked number one in the world, sued the country's federation in March with allegations of gender discrimination with complaints about wages and working conditions.
The U.S. players said they have been consistently paid less money than their male counterparts even though their performance has been superior to the men's team and Kirby said winning the World Cup allowed them to make such demands.
"The USA are in dispute at the moment but they're selling out arenas," the 25-year-old added. "They've won the World Cup and have some of the best players in the world in their team. They're in a position to do that."
England begin their World Cup campaign in Group D against Scotland on June 9 before taking on Argentina on June 14 and 2011 champions Japan five days later.
(Reporting by Rohith Nair in Bengaluru, editing by Pritha Sarkar)
