An Obama administration envoy for closing the Guantanamo Bay prison confirmed Wednesday that Americans have died as a result of the release of an unspecified number of prisoners from the facility.

Paul Lewis, the Department of Defense's special envoy for Guantanamo Closure, told a House Foreign Affairs Committee that some Americans have died at the hand of at least one released detainee, although he would not say in an unclassified setting exactly how many or the circumstance surrounding their deaths.

"Less than five percent of detainees released since January 2009 are confirmed of re-engaging in terrorism and, of those, none are assessed to have killed Americans," a senior administration official told the Washington Examiner.

The official was referring to the percentage of terrorists released by the administration confirmed of returning to the fight, according to a recent report by the Office of the Director of National Intelligence. The number of those confirmed to have returned as well as those suspected to have returned is higher, approximately 8 percent, and Republicans point out that U.S. intelligence investigators have said it takes four years to confirm whether the terrorists have definitely returned or not.

In admitting that a released Guantanamo Bay detainee had gone on to kill Americans, Lewis was responding to a question from Rep. Dana Rohrabacher, R-Calif., who asked how many lives have been lost by terrorists who went back to fight after the U.S. government released them from the prison at Guantanamo Bay. Lewis first said he could only talk about the incidents in a classified setting, a statement Rohrabacher challenged.

"Classified?" he asked. "Is it over 10?"

"What I can tell you is that unfortunately, there have been Americans who have died because of [released] Guantanamo detainees," Lewis said.

Rohrabacher argued back that the administration is allowing for the deaths of "innocent people" in their calculations over releasing detainees from the facility.

"As far as I'm concerned, if one child is saved because she would have been blown up by someone being released, it's better to keep all 90 of those people in Gitmo," Rohrabacher responded, adding that the scenario "disgusts" him.

There are currently 91 remaining detainees at Guantanamo Bay, 36 of whom have been cleared for release and another 10 who are in the middle of a military commission trial. The rest are detainees that the administration has deemed unworthy of release, according to the Obama administration.

Another administration envoy testified that he is confident that the governments of Ghana and Uruguay have the security needed to monitor Guantanamo detainees the U.S. government has recently transferred there.

"We only have admittedly several months of experience" with Ghana's handling of detainees, said Lee Wolosky, the State Department envoy for Guantanamo closure. "But I can tell you in this open forum ... is that we very pleased by the implementation by the government of Ghana of the security assurances."

Moments before, Wolosky flatly stated that "no transfer occurs unless we are confident in the security assurances that we have received."

Wolosky was responding to questions from Rep. Ed Royce, R-Calif., who chairs the panel. Royce said he's worried about the Obama administration's decision to send detainees to El Salvador, Kazakhstan and Ghana, all countries he said likely lack the infrastructure and security apparatuses to keep track of detainees.

Royce said Wednesday that he believes the Obama administration is tricking countries into accepting dangerous detainees.

Rohrabacher dismissed arguments from the Obama and George W. Bush administrations that the facility should be shuttered because it serves as a terrorist recruiting tool.

"I think the better recruiting tool today is when our government, especially this administration, is perceived as being weak," he said. "I think terrorists are recruited not because we've held other terrorists in prison, but because we look like we're weak and cannot deal with the challenge."

The California Republican suggested that the attitude, European allies and "some others" pressing the U.S. to close the island prison "may well be changing in the next six months or so when they realize the slaughter that is taking place in Paris and now in Brussels, Belgium, is part of an international movement to destroy Western civilization and replace it with a caliphate."