WASHINGTON — The Trump administration is pulling $271 million in funding from the Department of Homeland Security, including the Federal Emergency Management Agency's Disaster Relief Fund, to pay for immigration detention space and temporary hearing locations for asylum-seekers who have been forced to wait in Mexico, according to department officials and a letter sent to the agency by a California congresswoman.

To fund temporary locations for court hearings for asylum-seekers along the southern border, ICE would gain $155 million, all from FEMA’s Disaster Relief Fund, according to the letter from Rep. Lucille Roybal-Allard, D-Calif., which was seen by NBC News.

The allocations were sent to Congress as a notification rather than a request, because the administration believes it has the authority to repurpose these funds after Congress did not pass more funding for ICE detention beds as part of an emergency funding bill for the southwest border in June.

Click here to read the notification.

Specifically, the Department of Homeland Security will lose $116 million previously allocated for Coast Guard operations, aviation security and other components in order to fund nearly 6,800 more beds for immigrant detainees, the officials said.

“We would not say this is with no risk but we would say that we worked it in a way to…minimize the risk. This was a must pay bill that needed to be addressed,” said a DHS official, who noted that the funds would begin transfer immediately to fund ICE through Sept. 30.

Combined with existing space, the funding would allow ICE to detain nearly 50,000 immigrants at one time.

The Trump administration has claimed that the sudden rise in border crossings in 2019 has overwhelmed resources at the border, and that the lack of detention space at ICE has caused backlogs at border stations that offer migrants substandard conditions.

In July, there were 82,049 undocumented migrants who were apprehended or presented themselves at the southwest border, a sharp decline from over 144,000 in May, but still double the number seen the same month the previous year.

The $155 million for court hearings was originally allocated to FEMA in 2006 and 2007, but would have been used in the current budget to prepare to respond to natural disasters, such as hurricanes.

The administration began sending Central American migrants back to Mexico to await their court hearings in the U.S. as a means of slowing down the number of asylum-seekers who present themselves for asylum and remain in the U.S. until their court hearing. The funding will allow those immigrants waiting in Mexico to have their cases heard at the border, rather than being transported to locations within the interior of the country.

“I object to the use of funds for that purpose because the Department has provided no substantiation for a claim that this transfer is necessary due to ‘extraordinary circumstances that imminently threaten the safety of human life or the protection of property,’” Roybal-Allard said, referring to a provision that would allow DHS to repurpose funds at this point in the budget cycle without notifying Congress.

Sen. Jon Tester of Montana, the ranking Democrat on the Senate Appropriations Subcommittee on Homeland Security, also expressed reservations about the administration's plan.

"I have grave concerns about DHS's proposed end-run around laws passed by Congress that would drain millions from agencies tasked with protecting the homeland from security threats and natural disasters like hurricanes and wildfires — including CBP, TSA, FEMA and the Coast Guard," Tester said in a statement.

"Congress has already deliberated DHS's request and appropriated the highest-ever funding for border security and immigration enforcement, which passed on a bipartisan basis and was signed by President Trump," he added.