The U.S. women’s hockey team gathers on ice before a game at the Sochi Winter Olympics in 2014. (Jonathan Nackstrand/Agence France-Presse via Getty Images)

The U.S. women’s hockey team is scheduled to begin world championship play with a first-round game Friday night, but USA Hockey opened the week still with no players willing to take the ice.

With the clock ticking, the organization’s executive board met throughout Monday to weigh its options, facing mounting political pressure and a vow from the national team players to boycott the year’s biggest tournament until a resolution is struck over pay and resources afforded to the women’s program.

While USA Hockey has reportedly explored the option of utilizing replacement players, no formal announcement was made Monday night about the organization’s plans.

Also Monday, 20 Senate Democrats sent a letter to USA Hockey, saying members of the women’s national team “deserve fairness and respect” and urging the organization to resolve its dispute with the players over pay.

The women’s team has vowed to boycott next week’s world championships if USA Hockey doesn’t address the players’ concerns over what they feel is inadequate compensation and support. USA Hockey doesn’t pay the women in non-Olympic years and pays them $6,000 each in the year leading up to a Winter Games.

“We are disturbed by reports from the U.S. Women’s National Hockey Team suggesting that USA Hockey is not providing ‘equitable support’ to female athletes,” the senators wrote.

The letter was addressed to Dave Ogrean, the executive director of USA Hockey, and delivered Monday. The senators who signed the letter include Sen. Elizabeth Warren (D-Mass.), Sen. Patrick J. Leahy (D-Vt.), Sen. Cory Booker (D-N.J.), and Sen. Robert P. Casey Jr. (D-Pa.).

They wrote: “While USA Hockey provides its male athletes with a ‘seemingly endless’ supply of hockey equipment, for example, female players are often expected to ‘buy their own.’ This ‘inequitable support for equipment, staff, meals, travel expenses, transportation, and publicity’ is apparent at younger levels of the sport as well: while USA Hockey spends $3.5 million to support male youth athletes in its National Team Development Program, there is no parallel development program for women.”

The men’s team similarly isn’t paid in non-Olympic years, but that squad is typically composed of well-compensated NHL players. The women’s players don’t have the same sources of revenue.

The players have found support from many corners of the hockey world in recent days. Some have suggested the men’s team could similarly boycott its world championships in solidarity.

And last week all four major sports unions issued statements of support. “It is important that the best American women players be on the ice for the World Championship and the notion of seeking replacement players will only serve to make relations, now and in the future, much worse,” the NHL Players Association said.

“These women understand inequality when they see it and are expressing their right to be treated fairly as athletes and workers,” said DeMaurice Smith, the executive director of the NFL Players Association. “Of course, they have our support in daring to withhold their services until a fair agreement is reached.”

The United States is the defending champion in the world championships, which begin Friday in Plymouth, Mich.

In their letter, the senators noted that the Ted Stevens Olympic and Amateur Sports Act requires USA Hockey to “be responsible to the people and amateur sports organizations it represents.” The organization is “also legally required to ‘provide equitable support and encouragement for participation by women where separate programs for male and female athletes are conducted on a national basis,’ ” according to the letter.

“These elite athletes indeed deserve fairness and respect, and we hope you will be a leader on this issue as women continue to push for equality in athletics,” the senators wrote.

USA Hockey executive board meets, but boycott by women’s team still looms