The United States has more than doubled the number of detainees both those deemed to be a "high threat" as well as others slated for deportation at the U.S. naval base at Guantanamo Bay, Cuba.

As of Tuesday, there were more than 120 of what the administration calls "criminal aliens" under guard at the detention facility at Guantanamo Bay, according to a U.S. defense official.

Approximately 50 other individuals are also being held at the base's migrant facility, which was being readied to hold nonviolent individuals.

Separately, a second U.S. defense official told VOA that as of Monday, the U.S. military had sent a total of 13 flights of undocumented migrants to Guantanamo aboard a mix of C-17 and C-130 military cargo jets.

So far, none of the detainees brought to the facilities at Guantanamo Bay have been deported to other countries.

Both officials spoke to VOA on the condition of anonymity in order to discuss details of the military's deportation operation.

VOA has also reached out to the Department of Homeland Security, which is spearheading the U.S. deportation efforts, as well as Immigration and Customs Enforcement, about the growing number of detainees.

Last Thursday, the commander of U.S. Southern Command, which oversees operations at the naval base at Guantanamo Bay, told lawmakers there were about 68 detainees at the base's prison facility.

Admiral Alvin Holsey also told lawmakers that the base's migrant facility had the capacity to hold about 2,500 nonviolent detainees. Efforts are underway to allow it house as many as 30,000 nonviolent migrants slated for deportation.

Holsey said that it was too soon to determine how much it will cost to house the growing number of individuals.

"We're working with DHS to understand the flow of migrants," he said during Thursday's hearing before the Senate Armed Services Committee. "We're not going to go to 30,000 unless we know that migrant flow will come. So, we're waiting at this point."

Details about the growing population of detainees at the U.S. naval base in Cuba come just a day after the Department of Homeland Security unveiled what it described as a multimillion-dollar ad campaign warning migrants not to enter the U.S. illegally.

"If you are considering entering America illegally, don't even think about it," Homeland Security Secretary Kristi Noem said in a video targeting an international audience.

"If you come to our country and you break our laws, we will hunt you down," she said. "Criminals are not welcome in the United States."

Noem, who visited the prison facility last Friday and oversaw the transfer of a third flight of detainees to the detention center, has repeatedly described the men as "murderers and vicious gang members" from Venezuela and as "the worst of the worst."

In one social media post, Noem said that at least one of the migrants sent to Guantanamo Bay had confessed to murder, while others were wanted for attempted murder, assault, weapons trafficking and impersonation.

One official, speaking to VOA on the condition of anonymity to discuss the deportation efforts, said that all of the individuals held at Guantanamo Bay have been issued final deportation orders. But DHS has not yet provided charging documents or other details regarding the crimes the detainees are accused of committing.

Last Wednesday, the American Civil Liberties Union, along with several immigration rights groups, filed a lawsuit against DHS, alleging the detainees being held at the Guantanamo Bay prison facility have been improperly denied access to lawyers.

DHS has dismissed the lawsuit's allegations.

"There is a system for phone utilization to reach lawyers," said a senior Homeland Security official in a written statement shared with VOA.

"If the AMERICAN Civil Liberties Union cares more about highly dangerous criminal aliens including murderers & vicious gang members than they do about American citizens they should change their name," the official added, responding to the lawsuit only on the condition of anonymity.