By Nicole Gaouette and Laura Koran, CNN

(CNN) -- Trump administration officials told Congress that there's no need to update the authorization that was originally meant to counter terrorists responsible for Sept. 11, 2001 and has now been stretched to cover anti-terror operations in over a dozen countries.

A new Authorization for the Use of Military Force "is not legally required to address the continuing threat posed by al Qaeda, the Taliban, and ISIS," Defense Secretary James Mattis told the Senate Foreign Relations Committee.

But many lawmakers and human rights groups feel that the AUMF has been stretched far beyond its original purpose, 16 years after it was first drafted, to justify military activity in places like Niger, where four US troops were recently killed. Congress, they argue, should have a chance to review where and how the President is using military force.

Sen. Ben Cardin of Maryland, the senior Democrat on the committee, said he voted for the 2001 authorization, but added that, "I never intended, all of us never intended, it would still be used today to justify the use of military force against ISIS."

"I personally think 2001 doesn't apply to this situation," Sen. Ron Johnson, a Wisconsin Republican, said referring to the fight against ISIS.

Originally written to target those responsible for the 2001 attacks, critics say that it's now used to fight groups that didn't even exist in 2001.

Secretary of State Rex Tillerson said the 2001 AUMF provides the legal basis for holding members of al Qaeda, the Taliban and other groups at the detention facility in Guantanamo Bay. It also authorizes the use of "necessary and appropriate force" to defend the US and partner forces in the fight against ISIS in Iraq and Syria, Tillerson said.

"This administration relies on the 2001 AUMF as the domestic legal authority for our own military actions against" al Qaeda, the Taliban, and ISIS in Iraq and Syria, Tillerson told the committee.

Mattis and Tillerson argued that repealing the 2001 AUMF and a second 2002 AUMF tailored for Iraq would cause operational paralysis, confuse military operations and lead allies to question the US commitment to fighting ISIS.

Mattis said it, "would only cause unnecessary policy and legal uncertainty, which could lead to additional litigation and public doubt."

Tillerson added that repealing the 2001 and 2002 authorities without "an immediate and appropriate replacement would call into question the domestic legal basis for the United States' full range of military activities against the Taliban, al Qaeda and associated forces, including ISIS, as well as our detention operations at Guantanamo Bay."

"The uncertainty accompanying that situation could only signal to our enemies and our friends that we are backing away from this fight," Mattis said, adding that a repeal would "create significant opportunities for our enemies to seize the initiative."

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