Fifteen detainees have been transferred from the Guantanamo Bay detention facility in Cuba to the United Arab Emirates, the Pentagon said Monday.

It is the largest transfer during President Barack Obama’s term, said Lee Wolosky, U.S. special envoy for Guantanamo closure.

The move brings the number of detainees at the facility to 61 from 242 when Obama took office in 2009. The president at the time promised to shutter the complex, and renewed his pledge earlier this year with a new plan.

Congressional Republicans were quick to criticize the transfers of the 12 Yemenis and three Afghans. “In its race to close Gitmo, the Obama administration is doubling down on policies that put American lives at risk,” House Foreign Affairs Committee Chairman Ed Royce said, according to media reports.

“Once again, hardened terrorists are being released to foreign countries where they will be a threat,” he said. “I fear we will be dealing with the consequences of this recklessness for years to come.”

In a speech Monday on defeating Daesh, Republican presidential nominee Donald Trump vowed to keep open the controversial prison.

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