President Donald Trump said Wednesday he is ordering officials to establish a massive migrant detention facility at the Guantánamo Bay Naval Base in Cuba. He made the announcement during a signing ceremony for the Laken Riley Act, which allows authorities to detain undocumented immigrants accused of theft-related crimes.

Trump said the site would “detain the worst criminal illegal aliens” and be “a tough place to get out of.”

Guantánamo Bay, which is also the site of a prison that held terrorist suspects after the Sept. 11, 2001, attacks, has become a notorious symbol of U.S. excesses during the “war on terror,” including the brutal mistreatment of prisoners and detention of suspects for two decades without charge.

Human rights groups have condemned Trump’s move. “Migrants and asylum seekers are being cast as the new terrorist threat, deserving to be discarded in an island prison, removed from legal and social services and supports,” the Center for Constitutional Rights said in a statement. The group, which has represented a number of Guantánamo detainees, said it will continue to challenge the U.S. government’s use of the facility.

What is Guantánamo Bay?

Located on the southeastern coast of Cuba, Guantánamo Bay was seized in 1898 by U.S. forces and their Cuban allies during their efforts to wrest the island from Spanish control. The United States formally established a naval base on the bay in 1903, after leasing 45 square miles of land and water from the newly independent Cuban government, according to the U.S. Navy. It is the United States’ oldest overseas military installation and the only one in a communist country, the Navy has said.

In 1934, the United States signed a treaty with Cuba reaffirming the lease, which cannot be terminated without the consent of the two governments or unless the United States abandons the base.

President George W. Bush established a military prison at the base in 2002 to hold suspects accused of terrorism after the 9/11 attacks and the start of the U.S. war in Afghanistan.

For decades, “Gitmo,” as it came to be known, has been mired in controversy, particularly over allegations of torture — which Bush has broadly denied but a top official from his administration acknowledged — as well as the detention of hundreds of prisoners without formal charges.

In 2005, the nonprofit Amnesty International called it the “gulag [of] our times.”

Housing roughly 680 prisoners at its peak in 2003, Guantánamo has come under scrutiny for years-long detentions bogged down by the military’s bureaucratic justice system, which has been notoriously slow to move the case against the accused mastermind of the 9/11 terrorist attacks to trial.

Presidents Barack Obama and Joe Biden said they wanted to close Guantánamo. However, the prison remains open and is holding 15 detainees, Reuters reported this month.

What are Trump’s plans?

Trump wants to use the Guantánamo naval base to house detained migrants, and he has instructed the secretaries of defense and homeland security to expand the base’s Migrant Operations Center to “to full capacity.” Speaking at the White House on Wednesday, Trump said he has directed officials to start preparing what he described as “the 30,000-person migrant facility.”

Immigrant detainees will not be held with terrorism suspects, Defense Secretary Pete Hegseth told Fox News in an interview. The facility, Hegseth added, will be used to hold people while their deportation paperwork is processed and travel arrangements are made.

It was not immediately clear how migrants will be housed, what kind of construction will be required and what the operational costs might be.

Has it been used to house migrants before?

U.S. government agencies and private contractors have used facilities at Guantánamo Bay to detain asylum seekers and refugees for several decades, rights groups say

In 1994, for instance, President Bill Clinton resumed the previous administration’s use of the Guantánamo base for processing Haitian refugees and later ordered Cuban asylum seekers caught at sea to be held on the base. Later that same year, the facility’s migrant population totaled 45,000, according to a government report.

Last year, the International Refugee Assistance Project released a report accusing the U.S.-run Migrant Operations Center at Guantánamo Bay, or GMOC, of detaining migrants fleeing Haiti, Cuba and other Caribbean countries throughout its history. Many of those refugees are intercepted by the U.S. Coast Guard at sea and then “detained indefinitely in prison-like conditions without access to the outside world,” often “with little to no transparency or accountability,” the report said.

“These refugees are forced to endure this treatment until a third country agrees to accept them for resettlement, even if they have family in the United States,” it said, adding that the process can take years.

IRAP accused the U.S. government of subjecting detained migrants to “a multitude of health and human rights violations,” including “substandard living conditions, abusive guards and forced medical procedures including forcibly administering birth control.”

It’s unclear how many migrants and refugees are currently detained at GMOC, the IRAP said.

What detention space does the United States currently have?

The Guantánamo facility will far exceed the capacity of existing U.S. Immigration and Customs Enforcement facilities, the largest of which have about 2,000 beds. Overall, ICE has detention capacity for about 40,000 people.

About 1.4 million people in the United States are known to have deportation orders issued against them.

An estimated 11 million people are living in the United States without legal status, a 2024 report by the Department of Homeland Security said. ICE deported the highest number of people in a decade during fiscal year 2024, the last full fiscal year of Biden’s term.