The U.S. Secret Service was also a beneficiary of the reallocation.
Democratic Sen. Patrick Leahy of Vermont, the vice chairman of the Senate Appropriations Committee and a member of the Homeland Security subcommittee, sent a statement to NPR denouncing the "hefty price" of Trump's immigration policies.
DHS argues in the document that the impact on FEMA will be "minimal".
FEMA, TSA, ICE and the Coast Guard are all agencies within the Department of Homeland Security.
"Under no circumstances was any disaster relief funding transferred from @fema to immigration enforcement efforts", Houlton tweeted. The transfers were requested so ICE could add more than 2,000 detention center beds on top of 38,000 adult beds it predicted it would need in its initial budget request for the year.
Insufficient funding could require ICE to "release any new book-ins and illegal border violators", and prevent ICE from deporting those who have violated immigration laws, the document reads. The document mentions Fiscal Year 2018 but doesn't include an exact date.
The department then must notify the chairs of the relevant congressional appropriations subcommittees, who must approve.
"It does not come out of the disaster relief fund that funds everything behind me and in the field, so it's a non-issue for us at this moment", Long told ABC News.
"It means just as hurricane season is starting, and it usually starts June 1, the administration is working hard to find funds for additional detention camps and it's all part of the child separation policy".More news: Messi liked Busquets quickly at Barcelona - Guardiola
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It's unclear when the funds were transferred.
"We always plan one category higher than what's anticipated, and the main primary driver of the evacuations is coastal storm surge, flood inundation, wind-driven water coming up on shore", said Long. He also suggested that the financial pressure was linked to this month's announcement by the administration of new regulations created to enable expanded detention of families who cross into the US without legal status.
In the documents, it is stated FEMA "will curtail training, travel and public engagement in response to the cuts".
He also said that the transferred money came from routine operating expenses and "could not have been used for hurricane response due to appropriation limitations".
DHS records show that money transfers to ICE from FEMA and other Homeland Security agencies reduced funding for federal air marshals, screening dogs at airports, armored cars for federal investigators overseas, border security and E-Verify, which checks whether workers have legal papers.
The Oregon senator said the administration took $9.8 million from the Federal Emergency Management Agency's "response and recovery" and put it in the coffers of U.S. Immigration and Customs Enforcement.
Over the previous year there have been questions about whether FEMA's resources have been spread too thin as it responds to hurricanes - the $10 million has attracted attention, but it is a small portion of FEMA's annual $15 billion budget.
Trump said on Tuesday that the government was "absolutely, totally prepared" for the hurricane bearing down on the Carolinas.
The agency said it is prepared for Hurricane Florence, which is expected to hit North and SC, and Virginia on Thursday or Friday. "We're ready. We're able".
The almost $10 million was taken from various places within FEMA, including training, preparedness and protection, and response and recovery operations.
It was "one of the best jobs that's ever been done with respect to what this is all about", Trump said.