Secretary of Homeland Security Markwayne Mullin said the department has no near-term plan to shut down Alligator Alcatraz, even as he acknowledged the soft-sided Florida immigration detention facility is vulnerable to natural disasters.

"I don't think we've said we're shutting it down," Mullin said. "That's not been an announcement we've made." The secretary told CBS News in an exclusive interview that DHS understands "there's vulnerabilities" around the soft-sided facility in the middle of the Everglades, adding that "we have fires that are within 20 miles of it" and "Florida is pretty susceptible to hurricanes." 

Mullin's comments follow reports that companies hired by the state of Florida to operate Alligator Alcatraz were notified Tuesday that the facility is being shut down, with roughly 1,400 remaining detainees expected to be removed in the coming weeks. One source told CBS News Miami that "the last detainee will leave in June," amid escalating operating costs that are now estimated to total nearly $1 billion.

Pressed on whether there are any near-term plans to close the site, Mullin said DHS has contingency plans in the event of a natural disaster, but no plans to close the facility permanently. 

"We have plans in case of a natural emergency such as a wildfire or hurricane, to have to be able to bring it down and pull the individuals out," he said. But he added that DHS still needs the ability "to flex when we have a big influx" of migrants, calling the facility part of the department's needed "surge capacity."

On Wednesday, Gov. Ron Desantis said Florida has not received definitive notice from the federal government about whether the facility will close — or the road ahead. 

Florida Division of Emergency Management Director Kevin Guthrie told reporters Wednesday, "We have received zero communication formally saying, 'Hey, this is the path going forward. Here's how we're going to try to get there.' That has not happened."

The facility opened on a largely abandoned Florida airstrip last year. The Trump administration cast it as a cost-effective way of holding immigration detainees as it sought to ramp up arrests and deportations, but activist groups have criticized conditions at the facility, and it has drawn legal challenges from environmental groups and a Native American tribe.

A shift from warehouses to abandoned facilities 

At the same time, Mullin said DHS is looking to reshape its strategy of expanding detention capacity, amid scrutiny of warehouse-style detention centers. Asked about the DHS inspector general's probe of $38 billion in warehouse detention space within ICE, Mullin noted that some states are blocking DHS from using existing detention facilities, forcing the department to find its own space.

"We don't have a choice but to continue that," Mullin said, adding the department is "going to change the focus a little bit." Instead of only looking to convert warehouses into immigration detention facilities, Mullin said DHS is exploring use of county jails as well as shuttered state and local facilities that can be purchased, repaired and brought online more quickly. 

"Rather than just looking at warehouses, we're going to look at county jails that may be in default on their grants. We're going to be looking at facilities that have been shut down because they were too expensive to operate, because states or counties didn't have the budget to do maintenance… where we purchase them, bring them up and immediately have beds available," he said.

The secretary, citing his former background in construction, noted that converted warehouses can require permitting, utilities, water, gas and major build-outs — meaning some could take "18 to 24 months to bring online." That timeline, Mullin said, "doesn't fit today's need." 

A temporary leader for ICE

The secretary also confirmed DHS is moving to put a temporary leader in place at ICE while continuing its search for a permanent director. Acting ICE Director Todd Lyons is planning on leaving the federal government at the end of the month, CBS News previously reported.

Asked about CBS News' reporting that David Venturello will be the next acting ICE director, Mullin said he and Venturello have had "long conversations," but that DHS is "still actually looking for a permanent position for the director." 

"We want to put somebody there that's permanent," Mullin said. "David is great. David is going to be a good placeholder, but he'll be our deputy once we find someone to take the director's position."

DHS acknowledges debts owed to State, Pentagon, Interior after shutdown

The DHS secretary also addressed unpaid DHS bills to other federal agencies after a prolonged 76-day shutdown, acknowledging the department owes collective billions to the State Department, Pentagon and Department of Interior because they helped keep DHS operations running.

Earlier this week, Sen. Jack Reed of Rhode Island, the top Democrat on the Senate Armed Services Committee, warned at a congressional hearing that the Army is facing a $2 billion readiness shortfall tied to DHS' failure to reimburse the service branch for operations along the border. 

"We owe money to the State Department. We owe money to the Department of War. We owe money to the Interior because they were all keeping us afloat," Mullin conceded. He said that "as the money comes in, we're writing the checks and sending them out the door." 

Mullin pointed specifically to the U.S. Coast Guard, noting its operations were affected by unpaid fuel and utility bills, forcing reliance on the Defense Department. 

"Our gas card, literally, for the Coast Guard, got shut off," Mullin said. "We hadn't paid our gas bill or electricity bill or the fuel bill since February. So DOW helped the Coast Guard stand up."