The U.S. special envoy to Haiti dramatically resigned on Thursday in a letter that excoriated the Biden administration for deporting hundreds of migrants to the crisis-engulfed Caribbean nation from a camp on the U.S.-Mexican border in recent days.

Daniel Foote, a career diplomat named to his post in July, said conditions in Haiti were so bad that U.S. officials were confined to secure compounds. He said the "collapsed state" was unable to support the infusion of returning migrants.

"I will not be associated with the United States' inhumane, counterproductive decision to deport thousands of Haitian refugees and illegal immigrants," Foote said in a letter addressed to Secretary of State Antony Blinken that circulated publicly on Thursday.