Defense Secretary Ash Carter said during an interview aired Sunday that it is currently illegal to transfer detainees from the U.S. military prison at Guantanamo Bay, Cuba to the American homeland.
Carter hopes Congress will change the law to make it legal, however, and told CNN's Fareed Zakaria, who conducted the interview, that he submitted a plan to President Obama to close Guantanamo and move the remaining detainees to a secure facility in the United States.
"I've made a proposal for the president, and he has indicated that he's going to submit that to the Congress," Carter said. "Why is that? Because it's against the law now to establish another detention facility [in the U.S.], so therefore we have to get the support of Congress."
Attorney General Loretta Lynch has also said it would be illegal to transfer Guantanamo detainees to the U.S. under current law.
Carter expressed hope that Congress would support his proposal and called for people to be realistic about Guantanamo.
The Defense Secretary told Zakaria that because some Guantanamo detainees are too dangerous to ever be released to another country, the only option is to move them to the U.S.
"Here's the issue," Carter said. "There are people in Gitmo who are so dangerous that we cannot transfer them to the custody of another government no matter how much we trust them ... So the reality is that this portion of the Gitmo population has to be incarcerated somewhere."
Therefore, according to Carter, if the U.S. is going to close Guantanamo, the only place to move these detainees "would have to be in the United States."
Carter's statements came just over a week after he announced that he was preparing such a plan for President Obama to close Guantanamo.
President Obama has made it a priority to close the detention center since promising to do so during his 2008 campaign. He has said that Guantanamo, which opened in 2002, is not in keeping with American values and serves as a primary recruiting tool for Islamic terrorists to rally others to their cause.
Experts who study jihadist propaganda disagree with the president's assertion, arguing there is little mention of Guantanamo in terrorist recruitment efforts.
Gen. John Kelly, who just retired as the head of U.S. Southern Command, recently detailed to reporters how detainees at Guantanamo receive the best care possible and no ill treatment.
Opponents of the president's Guantanamo plan also say the military prison is necessary to hold enemy combatants from al Qaeda and other jihadist groups and gather intelligence from them. They add that the recidivism rate for released detainees who return to terrorist activities is 30 percent, a figure some Obama administration officials have disputed.
Carter told Zakaria he "completely agrees" with President Obama and "thinks on balance it would be a good thing to close Gitmo" because he does not want to leave the issue to the next president and secretary of defense.
The White House recently touted how it has lowered the Guantanamo population from 242 when the president took office down to 93 detainees, mainly by releasing the suspected terrorists to foreign governments to watch over them for a period of time.
Since 2009, Congress has included language in each annual defense bill prohibiting the transfer of Guantanamo detainees to the U.S. homeland.
The Pentagon is reportedly looking at prisons in Colorado as the most likely options to send the remaining Guantanamo detainees.