US President Joe Biden's special envoy to Haiti has resigned in protest of "inhumane" large-scale expulsions of Haitian migrants to their homeland as it is wracked by civil strife and natural disaster, US officials say.
Daniel Foote was appointed to the position only in July, following the assassination of Haiti's President Jovenel Moise.
Even before the migrant expulsions from the small Texas border town of Del Rio, the career diplomat was known to be deeply frustrated with what he considered a lack of urgency in Washington DC and a glacial pace on efforts to improve conditions in Haiti.
Foote wrote to Secretary of State Antony Blinken to say that he was stepping down immediately "with deep disappointment and apologies to those seeking crucial changes".
"I will not be associated with the United States inhumane, counterproductive decision to deport thousands of Haitian refugees and illegal immigrants to Haiti, a country where American officials are confined to secure compounds because of the danger posed by armed gangs to daily life," he wrote.
"Our policy approach to Haiti remains deeply flawed and my policy recommendations have been ignored and dismissed, when not edited to project a narrative different from my own."
The US State Department criticised Foote for resigning at a critical juncture and pushed back against suggestions that his policy prescriptions were overlooked.
"This is a challenging moment that requires leadership," spokesman Ned Price said in a written statement.
"It is unfortunate that, instead of participating in a solutions-oriented policy process, Special Envoy Foote has both resigned and mis-characterised the circumstances of his resignation."
He added that the role of the president's advisers is to provide him with the best possible advice.
"No ideas are ignored but not all ideas are good ideas," Price said.
Foote's sudden departure leaves a void in US policy toward Haiti - US ambassador Michele Sison is expected to depart soon after being nominated to serve in another State Department post - and adds another critical voice to the administration's response to Haitians camped on the Texas border.
Criticism has been fuelled by images that went viral this week of Border Patrol agents on horseback using aggressive tactics against the migrants.
Democrats and many pro-immigration groups say efforts to expel thousands of Haitians without giving them a chance to seek asylum violates US principles.
The migrant camp has shrunk considerably since surpassing more than 14,000 people on Saturday, with many of them expelled and many others released in the US with notices to report to immigration authorities.
The expulsion flights to Haiti began on Sunday and there were 10 by the end of Tuesday, according to Haitian officials.
US officials say they are ramping up to seven flights a day, which would make it one of the swiftest, large-scale expulsions from the US in decades.
Australian Associated Press
