President Donald Trump’s effort to transfer migrants from the United States to the Naval base at Guantanamo Bay, Cuba is being buffeted by concerns inside and outside his administration.

Trump promised to use a facility at Guantanamo Bay that could hold up to 30,000 people. But as the administration faces legal and financial hurdles, those plans seem to be collapsing.

The U.S. military has started making plans to draw down personnel deployed to the naval base in the coming weeks.

Trump’s failed operation to send migrants to Guantanamo Bay has already burned through at least $16 million, The Wall Street Journal reports. That figure does not include the wildly expensive flights—it costs more than $20,