WASHINGTON >> The Trump administration is ramping up plans to detain immigrants in the U.S. without legal permission at military sites across the country, a significant expansion of efforts by the White House to use wartime resources to make good on the president’s promised mass deportations.

President Donald Trump’s team is developing a deportation hub at Fort Bliss, near El Paso, Texas, that could eventually hold up to 10,000 immigrants as they go through the process of being deported, according to three officials familiar with the plan.

Fort Bliss would serve as a model as the administration aims to develop more detention facilities on military sites across the country — from Utah to the area near Niagara Falls — to hold potentially thousands more people and make up for a shortfall of space at Immigration and Customs Enforcement facilities, the officials said. They spoke on the condition of anonymity to discuss details of a plan that is still in its early stages and has not yet been finalized.

Previous administrations have held some immigrants at military bases, most recently children who would then be released into the country to the care of relatives or friends. The bases served as an emergency backup when the federal government’s shelter system for migrant children reached capacity.

But the Trump administration plan would expand that practice by establishing a nationwide network of military detention facilities for immigrants who are subject to deportation. The proposal would mark a major escalation in the militarization of immigration enforcement after Trump made clear when he came into office that he wanted to rely even more on the Pentagon to curtail immigration.

For Trump officials, the plan helps address a shortage of space for holding the vast number of people they hope to arrest and deport. But it also raises serious questions about the possibility of redirecting military resources and training schedules. Military officials say the impact would depend on the scale of arrests and how long detainees remained in custody. And advocates for immigrants point to a history of poor conditions for immigrants held in military facilities.

Gil Kerlikowske, the former commissioner of Customs and Border Protection, said military facilities are not designed for a project like this.

“It’s beyond odd,” Kerlikowske said. “Securing the people is labor-intensive, and it could also be resource-intensive.”

Trump has made the promise of mass deportation a centerpiece of his presidency after a campaign in which American voters across party lines shifted to the right on immigration.

So far, the Pentagon has deployed 5,000 active-duty troops and National Guard members to the southern border to assist the Border Patrol, with the goal of doubling that number in coming weeks.

It also flew a small number of migrants to Guantánamo Bay, Cuba, before transferring all of them this week to other countries. It has released photos and videos to promote Trump’s crackdown, including close-up shots of immigrants in shackles.

But the administration is not yet arresting immigrants at a rate that would fill a nationwide network of military facilities. ICE officers made more than 15,000 arrests between Jan. 21 and Feb. 13, according to the Department of Homeland Security. That’s an average of just under 700 arrests a day, more than double the typical daily rate in recent years, including during the Biden administration, but far short of what White House officials want.

It is not clear how many immigrants could be held at the various military facilities given that the Trump administration will likely develop new tent encampments on the space surrounding them. But the plans to rely on military bases in more than a dozen states would be a major expansion of detention capacity.

Once the administration finishes evaluating the detentions at Fort Bliss over about the next two months, it could start detaining migrants at other military bases, including Air Force bases, close to the border and then across the country as necessary. The facilities are in Florida, New Jersey, Utah, New Mexico, Colorado, Oregon, Minnesota, Wyoming, Washington and Northern California, and near Niagara Falls in upstate New York.

The Trump administration is strapped for detention beds to hold immigrants because of limited budget resources. As a result, ICE has generally detained around 40,000 individuals in private prisons and local jails across the country in recent weeks. That’s down from the first Trump administration, when the agency held more than 50,000 in ICE beds. The use of military resources and facilities throughout the country provides the agency with easy-to-access beds to hold immigrants soon after they are arrested by ICE agents.