House Speaker Paul Ryan is facing new pressure from lawmakers to schedule a debate on congressional authorization for the fight against the Islamic State. (AP)

A bipartisan group of 35 House lawmakers is pressing new House Speaker Paul D. Ryan (R-Wis.) to move forward with a long-stalled effort to provide the White House  with specific authority to fight the wars in Iraq and Syria.

More than a year after the United States began airstrikes against the Islamic State, Congress has yet to vote on authorizing the conflict amid fights among Democrats, Republicans and the White House over the language of the legislation. For Ryan, who has spent much of his career to budget outlays and the financial side of national security, the fight over the authority to wage war represents new territory. Ryan, who has a long history as a numbers guy, will have to play the role of foreign policy wonk.

"Americans are worried about the track we're on," said Rep. Jim McGovern (D-Mass.), one of the lead authors of the letter that went to Ryan. "They didn't elect us to give a blank check to the White House when it comes to war."

The letter also drew the support of 18 Republican lawmakers, including some of the most conservative members of the House, Rep. Mick Mulvaney (R-S.C.), a Freedom Caucus leader, Rep. Ryan K. Zinke (R-Mont.), a former Navy SEAL. and Rep. Tom Cole (R-Okla.)

"Each day we delay conversation and real action on this pressing matter is yet another day that ISIL grows stronger," Cole said, using a common abbreviation for the Islamic State.

The letter follows a joint raid conducted by U.S. and Iraqi counter-terrorism forces last month that freed as many as 70 captives being held by the Islamic State and resulted in the death of Army Master Sgt. Joshua L. Wheeler, the first American to die in Iraq since U.S. forces returned to the country last year. Last week, Obama said he was sending 50 Special Operations soldiers to Syria, marking the first full-time deployment of U.S. forces to the chaotic country.

"Taken all together, these represent a significant escalation in U.S. military operations in the region and place U.S. military personnel on the front lines of combat operations," the letter from the lawmakers states.

The letter's rare bipartisan backing is likely to grab attention on Capitol Hill, but probably isn't enough to break the gridlock on the war legislation. "We do not believe in the illusion of a consensus authorization," the letter states. "We do believe the Congress can no longer ask our brave servicemen and women to continue to serve in harm's way while we fail in carrying out our constitutional responsibility in the area of war and peace."

The letter, however, doesn't address the big divides that have prevented Congress from providing President Obama the authority to fight. Democrats have demanded legislation that would set tight limits on the war's scope, including a ban on ground combat troops and an expiration for the authority. Republicans don't want to take any actions that might limit the next president's ability to wage war.

The White House has said that the 2001 congressional vote to support action against al-Qaeda provides the authorization for the current conflict. But it has also said that it would welcome a formal authorization for the use of military force from Congress and even drafted  language for the legislation.

"The president of the United States sent some of his top foreign policy advisers, national security advisers to Congress to testify under oath in open hearings to explain to Congress what was included in the legislation and why they should pass it," White House press secretary Josh Earnest said last week.

"I don’t know when Congress is going to meet again," Earnest continued.  "I know they often take Fridays off and they often take Mondays off, so maybe on Tuesday they can have a meeting and a discussion about what should be on their agenda. And I’ve got an idea about what should be at the top of it."