The United States is planning to build its largest ever migrant detention facility on a military base in Texas.

The initial plan is to hold 1,000 migrants at the Fort Bliss base near the Mexican border starting this month, the Pentagon said on Thursday.

The facility, named Camp East Montana, would then be expanded to provide 5,000 beds for migrants in "the weeks and months ahead," according to the Department of Defense.

Migrant detention in tents at US base

When completed, it would be the largest federal detention center in the US, the Pentagon added.

The Defense Department is funding the detention center, which will consist of short-term tent-like housing, according to US media reports citing Immigration and Customs Enforcement (ICE).

Although the facility is being built on a military base, the Department of Homeland Security is expected to be responsible for the people held there, according to Reuters news agency.

US President Donald Trump has made the arrest and rapid deportation of undocumented migrants a key focus of his second term and masked, armed ICE agents have taken people into custody in raids at factories and farms around the country.

The number of migrants detained by Immigration and Customs Enforcement hit record levels in recent weeks.

Nationwide, nearly 57,000 people are being held in detention, according to ICE figures, which also showed the vast majority of those taken into custody have no conviction, despite the president's campaign promises to go after hardened criminals.

Trump administration using military amid migrant crackdowns

During Trump's first term, the Pentagon balked at building facilities to house detained migrants and the idea was dropped. 

His decision to activate the military in his second term is meeting with more success.

In July, Defense Secretary Pete Hegseth approved the use of two other military bases — in New Jersey and Indiana — to house migrants before their deportation.

Earlier this year, Trump ordered the preparation of a 30,000-person "migrant facility" at the Guantanamo Bay detention camp in Cuba earlier this year, though it has not held anywhere close to that number of people.

Trump's second term has also seen thousands of active-duty troops sent to the US-Mexico border.

Some migrants have also been deported using military aircraft, although this has reportedly been stopped on cost grounds.

In July, Congress approved $45 billion (€38.6 billion) for building new immigration detention centers.

Edited by Sean Sinico