A former senator of Haiti has pleaded guilty to plotting with others the assassination of the Caribbean islands's president in 2021, according to his plea deal with United States prosecutors.

Joseph Joel John, 52, admitted Tuesday in a Miami court to providing vehicles and other resources to support the plot to kill president Jovenel Moise, as well as meeting with several other conspirators in both Haiti and the US state of Florida, based on the plea agreement.

The US has jurisdiction in the assassination case because the plot was partly organized in Florida, home to a sizeable Haitian diaspora.

Two other conspirators earlier pleaded guilty after being indicted in July 2021 following Moise's assassination at his home near the Haitian capital Port-au-Prince.

Retired Colombian army officer German Rivera pleaded guilty in September to helping to carry out the murder of Moise, who was gunned down by a hired group of about 20 military-trained assassins, most of them Colombian. His security detail did not intervene.

Rodolphe Jaar, who holds dual Haitian and Chilean citizenship, pleaded guilty in June and was sentenced to life in prison for his role in supplying weapons to the mercenaries.

A US inquiry revealed that two managers of a Miami security firm, CTU, devised a plan to kidnap Moise and replace him with Christian Sanon, a Haitian American who wanted to become president of the impoverished Caribbean country.