Pentagon spent at least $21 million on flights to Guantanamo, which currently holds 32 migrants

The Trump administration spent at least $21 million transporting migrants to Guantanamo Bay on military aircraft between January 20 and April 8, according to figures provided to Congress by the U.S. military.

The naval base there currently holds 32 migrants, according to a defense official, a tiny fraction of the 30,000 that President Donald Trump promised. Guantanamo has held a total of just under 500 migrants since Trump announced the effort in January, and it has never held more than 200 at any one time. Many of the migrants flown there are believed to have been flown back to the U.S.

Democrats condemned the Guantanamo effort as a wasteful “political stunt” by Trump, who announced in late January that migrants would be held at the navy base, which houses the notorious detention facility. Two months after the effort began, administration officials acknowledged that it was logistically and legally flawed and beset by administration infighting.

Based on the flight figures provided to Congress, it has also proven costly. The average cost per flight hour for the military aircraft, for example, has been $26,277.

Sen. Elizabeth Warren, D-Mass., a member of the Senate Armed Services Committee, denounced the use of U.S. military assets and personnel for the mission.

“Every American should be outraged by Donald Trump wasting military resources to pay for his political stunts that do not make us safer,” Warren said. “U.S. service members did not sign up for this abuse of power.”

Pentagon officials did not immediately respond to a request for comment.

The Defense Department is preparing for an increase in capacity, with the U.S. Transportation Command recently ordering that an additional weekly flight to Guantanamo be added. The mission, formally named Operation Southern Guard, is led by the Department of Homeland Security and involves Immigration and Customs Enforcement officials, as well as the military.

Between January 20 and April 8, the U.S. military flew 46 flights that carried migrants on military aircraft. They lasted 802.5 hours, at a cost of approximately $21,087,300, according to information the Pentagon provided in response to questions from Warren.

Between January 20 and March 25, the Pentagon conducted 31 military and contract airlift flights that carried personnel, equipment and supplies to Guantanamo, they reported. They transported 715 passengers and 1,016.9 tons of cargo.

The contracted flights with passengers and cargo cost an additional $1,671,500, including over $660,000 paid to United Airlines and nearly $500,000 paid to Omni Air International, a charter company based in Tulsa, Oklahoma. None of these contracted flights carried migrants, according to the information provided to Congress.

This article was originally published on NBCNews.com