The group, led by Sen. Jerry Moran of Kansas, is also urging the new administration to suspend the review board set up by the Obama administration to approve prisoner transfers out of the facility.
"We want to express our support for maintaining and expanding the utilization of the detention facility during your administration by detaining current and future enemy combatants who pose a threat to our national security," the senators write.
The letter comes as Trump administration officials have been mulling over an executive order laying out how the new national security team plans to deal with the prison and its detainees. The details of that order have not been finalized, and several congressional aides say they have been mostly left out of the loop on the process of drafting the new order.
The role of Guantanamo Bay was a flashpoint of the 2008 presidential election, with Democrats -- and even some Republicans -- questioning its efficacy and whether the legal process put into place was adequate to ever actually produce convictions.
Trump, during his presidential campaign, made clear he wanted to reverse the course pursued by his predecessor with the facility. Obama came into office in 2009 pledging to shut down Guantanamo entirely, only to run into resistance on Capitol Hill, where the Republican-led Congress repeatedly passed legislation barring the Defense Department from transferring inmates onto US soil.
That led to a stalemate for an administration seeking a way to move inmates deemed ineligible for release by the review board into US prisons.
But that didn't stop the administration's efforts to relocate those that were deemed eligible for transfer by the review board. Obama came into office with 242 detainees at the facility. By the time he departed, only 41 remained after a push that led to the transfer of 19 detainees after Election Day alone. An additional four inmates have undergone the security review process and are eligible for transfer -- something Trump himself has hinted would be extremely unlikely.
"There should be no further releases from Gitmo," Trump tweeted January 3, using the shorthand for the facility. "These are extremely dangerous people and should not be allowed back onto the battlefield."
At its peak, the prison's population reached 684 detainees in 2003.
The senators are pushing a "full and judicious review" of the review board's "role and responsibilities," according to the letter -- a process that would undercut any efforts to relocate any of the remaining detainees. As the requested review takes place, the senators request "an immediate suspension" of any actions that would permit the transfer or release of any remaining detainees.
One of the primary concerns among GOP officials has been the ability of transferred detainees to make their way back onto the battlefield. The Office of the Director of National Intelligence, which tracks recidivism among former inmates, said in a September report that nine of 161 inmates released since January 2009 had returned to supporting terrorist groups. An additional 11 are "suspected" of having gone back to terrorist activity, though the report notes that the Defense Intelligence Agency puts that number at 15.
The signatories include several members of the crucial Senate Armed Services Committee and Senate Appropriations Subcommittee on Defense, including Sens. Tom Cotton of Arkansas, Roy Blunt of Missouri, James Inhofe of Oklahoma, John Boozman of Arkansas, Tim Scott of South Carolina, Cory Gardner of Colorado, Thom Tillis of North Carolina, Pat Roberts of Kansas, Steve Daines of Montana and Orrin Hatch of Utah.