WASHINGTON — While Congress is asking questions about President Donald Trump's latest military strikes in Syria, they are simultaneously preparing to wrestle with the United States's role in a series of ongoing conflicts around the world in the 17-year-long war on terror.

Two senators unveiled an updated war authorization Monday evening that would allow the president to extend the war on terror in places such as Afghanistan, Somalia and Yemen where the U.S. is fighting terrorism groups, but it is also an effort to place new checks on the president in what has been an open-ended, multi-faceted conflict.

The new proposal, negotiated by Sens. Bob Corker, R-Tenn., and Tim Kaine, D-Va., is the latest attempt to modernize and replace the 2001 war authorization passed by Congress in the days following the September 11 attacks that launched a consistently expanding conflict with U.S.-designated terrorist organizations around the world. The prospects for passage through the House and Senate is unclear but Corker wants it to be brought up in the Senate Foreign Relations Committee before the end of April.

Corker, chairman of the Foreign Relations Committee, said he's not focused on opposition that might be coming from members of his party.

"I don’t really worry about much beyond having a successful mark up in committee, which has been difficult for years," Corker said.

Supporters praise it as the last, best chance to redefine and limit the president's broad war authority as all previous efforts to pass a new war authorization have failed. But it has some expressing concern that it gives the president too much power to wage an unlimited war as it gives the administration the ability to continue conflicts against stateless terrorism organizations and start new ones.

"We’ve given the executive a blank check on where, when and who, and this imposes significant limitations on the where, when and who but tries to do it in a way that can get bipartisan support," Sen. Kaine told reporters.

Some members of Congress have called on Trump to seek congressional approval for further military action in Syria, but this authorization would not address that conflict or others that fall outside of expressly fighting terrorist organizations.

Unlike the current war authorization, a congressional review is built in every four years at which point Congress could amend, expand or repeal the president's authority. If Congress doesn't act, the president's authority continues unabated. While some wanted an expiration, negotiators settled on the review to ensure Congress has some oversight while trying to appease those reluctant to challenge the president's authority.

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Also in the measure: It specifically names terror groups the United States can engage, and it allows for the U.S. to fight the main terrorism splinter groups, known as "associated forces." If the president wants to add a new associated group, it must immediately be reported to Congress, which can disapprove.

The groups identified in the legislation are ISIS, al-Qaeda and the Taliban. How to define "associated forces" was the final sticking point before a final deal was reached, two sources and one senator told NBC News. Negotiators settled on a definition as non-state actors who have engaged U.S. forces first.

By not outlining regions where sustained combat fighting is allowed, the measure enables the administration to wage war against non-state actors anywhere in the world. But the president would be required to submit a report to Congress within 48 hours when he or she launches a new offensive. Congress can then disapprove, sources said.

“I think it strikes a pretty clear balance. I would have liked a sunset but this still gives us an opportunity to weigh in,” Sen. Jeff Flake, R-Ariz., who has worked on this measure and previous versions with Sen. Kaine, said. “So I think it strikes the best template that we could come up with.”

Critics say that while the current AUMF has been abused and must be updated, they worry this version still provides too much power to the executive branch.

“I worry about an AUMF that is more permissive than what the president currently interprets his authority to be,” Sen. Chris Murphy, D-Conn., said. “It’s gonna be hard for me to support something that has no sunset and no geographic limitation.”

Matthew Waxman, professor at Columbia Law School and former national security official in the George W. Bush administration said the lack of an expiration date will be disappointing to those who worry that this "entrenches an indefinite war."

"The political reality, though, is that a much more restrictive AUMF won't be possible anytime soon, and we'll be engaged in an indefinite war either way," Waxman said. "A new AUMF that includes strict congressional reporting and requires more frequent congressional reconsideration at least improves transparency and oversight."

The measure is being deliberated as the Trump administration launched a response to Syrian President Bashar al-Assad’s latest apparent use of chemical weapons against civilians. While such action does not fall under the authorizations of the AUMF, it adds to an ever-complex battlefield dynamic where the U.S. is already targeting radical groups like the Islamic State group in Syria.

Trump has repeatedly stated his aversion to using the U.S. military in wars abroad, but he is increasingly finding it difficult to disengage. The White House did not respond to questions about whether the president supports a new AUMF.

Trump said earlier this month that he wanted U.S. troops who are fighting terrorism out of Syria by the fall. His desire for a rapid withdrawal faced unanimous opposition from the Joint Chiefs of Staff, the Pentagon, the State Department and the intelligence community, which argue that keeping the 2,000 U.S. soldiers currently in Syria is key to ensuring the Islamic State does not reconstitute itself.

The Obama administration had argued that the 2001 AUMF, which allowed for the invasion of Afghanistan, and the 2002 Authorization for Use of Military Force Against Iraq Resolution provided the required authorization for certain U.S. military strikes against the Islamic State in Iraq and Syria, as well as the Khorasan Group of al-Qaeda in Syria, groups the administration said were affiliates of al-Qaeda.

Congress has tried to pass updated war authorizations in the past but administrations, including President George W. Bush’s and President Barack Obama’s, have opposed them as they’ve happily relied on the broad-scoped authorizations.

Sen. Bob Corker. Zach Gibson / Getty Images

Sen. Corker hopes the Senate Foreign Relations Committee could take up the measure within the next two weeks, but the ranking member of the committee, Sen. Bob Menendez, D-N.J., said he thinks the measure should move slowly and that a hearing should be held.

“One of the most important votes any member of Congress will ever take — authorization for the use of military force is about sending America’s sons and daughters abroad," Menendez said.

Sen. Chris Coons, D-Del., said the AUMF is not his "ideal version," but he called it a "credible bipartisan option.

"I think it's long overdue for the Senate to take up and debate an AUMF that could pass the Foreign Relations Committee and could be considered by the Senate," Coons said.