Four men were transferred from Haiti to the United States Tuesday to face criminal charges in the July 7, 2021, assassination of Haitian President Jovenel Moise, the US Justice Department announced.

The department said Haitian-American dual citizens James Solages, 37 and Joseph Vincent, 57, and Colombian citizen German Alejandro Rivera Garcia, 44, are charged with conspiring to commit murder or kidnapping outside the United States.

A fourth man, Haitian-American Christian Sanon, 54, is charged with smuggling ballistic vests from the United States to Haiti for use in the assassination plot.

The four will appear in federal court in Miami on Wednesday.

The US Justice department has already charged three others in the assassination, with Sanon, who the department called an "aspiring political candidate," a key leader of the operation.

It said Sanon recruited about 20 Colombians with military training and led by Rivera Garcia to help carry out the assassination.

The Colombian squad shot Moise dead on the night of July 6 to 7, 2021 in his private residence in Port-au-Prince.

"On July 6, 2021, Solages, Vincent, Rivera and others met at a house near President Moise's residence, where firearms and equipment were distributed and Solages announced that the mission was to kill President Moise," the department alleged.

US law is being applied in this case because the plan to kill the Haitian president was allegedly partly organized on US soil in Florida, by American-Haitian nationals.

The three charged with the assassination, along with three men arrested last year, face up to life in prison.

Sanon faces up to 20 years for his role in supplying the operation.