Washington ? Looking to breathe life into President Barack Obama’s stalled pledge to close the Guantanamo Bay prison, White House advisers are inching toward recommending military trials for alleged Sept. 11 mastermind Khalid Sheik Mohammed and four accused henchmen.

Attorney General Eric Holder’s original plan to try them in a civilian court in New York City met with criticism so fierce that it threatened to derail Obama’s promise to shut the U.S. military’s Cuban prison.

As difficult as the politics are concerning how and where to try the most notorious terror suspect in U.S. custody, that’s only one step toward the even more fraught and complicated goal of closing Guantanamo where Mohammed and nearly 200 other terror detainees remain.

Closing Guantanamo was a signature promise of Obama’s presidency, and it is still unkept well past his original deadline of January. Failing to keep it would have huge implications for the president, both with his base of supporters in the Democratic Party and in his efforts to remake America’s image around the globe.

Holder decided in November to transfer Mohammed and four other accused Sept. 11 terrorists from Guantanamo to New York City for civilian trials. City officials initially embraced the idea.

But they later reversed themselves, citing the high costs, security concerns and logistics of hosting a 9/11 trial — making things awkward for the Obama administration.