Thousands of other Haitian migrants, however, have been allowed to enter the United States and will wait for their cases to go through the backlogged immigration court system.
Mr. Foote said in his resignation letter that his recommendations were “ignored and dismissed.”
“Our policy approach to Haiti remains deeply flawed,” he wrote.
In response, the State Department’s spokesman, Ned Price, said that some proposals for dealing with Haiti’s compounding instability over the summer were rejected, and were “even harmful to our commitment to the promotion of democracy in Haiti.”
“No ideas are ignored, but not all ideas are good ideas,” Mr. Price said. He did not elaborate.
The Biden administration’s approach to Haiti was somewhat unusual, said Representative Andy Levin, Democrat of Michigan, in that Mr. Foote was appointed as special envoy to the nation even though a Senate-confirmed ambassador already had been serving there. The ambassador, Michele J. Sison, was nominated in April for a senior job at the department’s headquarters in Washington, but her confirmation has been stalled.
Mr. Levin, a chairman of the House Haiti Caucus, said the Biden administration was “propping up” the government of Ariel Henry, Haiti’s acting prime minister, who was accused last week of being linked to Mr. Moïse’s assassination. Mr. Henry swiftly removed the country’s chief prosecutor, who had leveled the accusation, setting off a power struggle among political factions as Haitians struggle to survive. Mr. Henry has denied any connection to the murder.
Mr. Levin said the Biden administration had fallen far short of helping empower civil society, religious leaders and human rights groups in Haiti who oppose Mr. Henry’s government or have otherwise demanded reforms.
“The Haitian people are crying out for the opportunity to chart their own country’s future, and the United States is ignoring their pleas,” Mr. Levin told reporters on Thursday.