The head of FEMA on Wednesday accused a Democratic senator of "playing politics" for claiming that the Trump administration had diverted $10 million from the agency to U.S. Immigration and Customs Enforcement to support immigration enforcement.

Brock Long, administrator of the Federal Emergency Management Agency, defended the transfer in an interview on MSNBC's "Andrea Mitchell Reports," saying that it had nothing to do with response efforts and that the agency spends billions of dollars to manage disasters. FEMA's annual budget is estimated to be $15 billion.

"Right now, that money has nothing to do with what you see behind us," he said in an interview from the FEMA response center in Washington. "It does not pay for this response, it is not coming out of the disaster relief fund, it has no impact on our efforts to be prepared for Hurricane Florence. It's just, unfortunately, we have a congressman that is playing politics on the back of Florence. There's no story there."

The story broke Tuesday night on MSBNC's "The Rachel Maddow Show," when Sen. Jeff Merkley, D-Ore., alleged that money earmarked for disaster relief and emergency response efforts had been taken out of FEMA's accounts and shifted to ICE.

The transfer occurred this summer and such transfers between government agencies are not unusual. However, the movement of the funds is raising questions about FEMA's preparedness as Hurricane Florence charges toward the Carolinas and Virginia. Roughly 1.7 million people in the Carolinas and Virginia have been told to evacuate.

Merkley said Wednesday that the Trump administration is not taking its job serious seriously regarding disaster response and preparedness.

"I think it came as a shock to everyone that in the first month in the hurricane season, knowing what happened a year ago, that FEMA agreed to have $10 million taken out of its accounts, including significant amounts out of its response and recovery account and another significant amount out of its preparedness and protection account," he said. "So those are very relevant for responding to disasters, such as the approaching challenges from Hurricane Florence that's approaching the shore."

He claimed that the money moved to ICE was "to build more prison camps" for undocumented immigration at the U.S.-Mexico border. "I think what the American people would like to hear is what can we learn from Puerto Rico, from the Virgin Islands and from Texas, so we can do it better," he said.

The Department of Homeland Security pushed back against Merkley's claims on Wednesday, saying that the funds were unspent money from operational accounts for training, office supplies and headquarters costs, which cannot be spent on disaster response, according to The Associated Press.

Sen. Patrick Leahy, D-Vt., said: "It has been no secret that President Trump's obsession with his wall, mass deportation, and the indiscriminate detention of children comes at a hefty price — a price that robs our country of its values and its resources. This case is no different, and now our Eastern Coast is left even more vulnerable in the path of Hurricane Florence."