Thousands of Haitian migrants are camping in the remote Texas city of Del Rio.
The US government has plans to swiftly send them back.
According to an official, three flights have already left San Antonio for Port-au-Prince.
The US has also blocked the border at Del Rio.
The Haitian prime minister, Ariel Henry, wrote on Twitter that he was concerned about conditions at the border camp and that the migrants would be welcomed back.