A mass release of Guantanamo Bay detainees announced Monday will likely affect negotiations of this year's National Defense Authorization Act, pushing lawmakers to keep tighter transfer restrictions in place, according to one expert.

Justin Johnson, an analyst with the Heritage Foundation, said aggressive moves by the administration, like the transfer of 15 detainees this week, will make it harder for those who support closing the detention center to make their argument and likely increase restrictions on transfers as House and Senate staffers negotiate differences between the two versions of the bill while lawmakers are in their home states.

"As long as the administration is making aggressive moves on Gitmo, I think Congress is not likely to take that very well and will likely tighten some of those restrictions," Johnson told the Washington Examiner. "The House bill was already adding back in restrictions from previous years … this only heightens that dynamic."

The House bill maintains a blanket ban on transferring detainees to the U.S. or using any money to build or retrofit facilities to house detainees. The Senate's version of the fiscal 2017 NDAA would loosen some of these restrictions by allowing detainees to come to the U.S. for medical care, which can be expensive to provide at the island's detention center.

The administration gave Congress a plan to close the detention center this year, but it didn't gain any traction in Congress since lawmakers didn't want detainees housed in their home states and because it lacked details. The Senate defense policy bill would also let the administration use money to flesh out details of the plan.

The Pentagon announced on Monday night that it had transferred 15 Guantanamo Bay detainees to the United Arab Emirates, bringing the total population of the detention center down to 61.

Some of those men fought on the frontlines against U.S. and coalition troops in Afghanistan, according to an unclassified report released last week by Sen. Kelly Ayotte, R-N.H. One, Hamid al-Razak, likely ordered and conducted attacks against Afghans and other coalition troops during Operation Enduring Freedom, according to the report.

Several among the 15 released also served as body guards for Osama bin Laden.

"As the administration continues to irresponsibly release detainees, the American people have a right to know how dangerous these terrorists are, which is why I'll keep pushing not only for more transparency, but also to keep Guantanamo Bay open so we can keep these terrorists out of the United States and off the battlefield," Ayotte said in a statement.