1941-12-08
Lescot declares war on Japan the day after Pearl Harbor
Haitian
On 8 December 1941 President Élie Lescot declared war on Japan, with the unanimous approval of the permanent Committee of the National Assembly. A state of siege was declared across Haiti the same day, and the authorities warned that any saboteur would face a court martial and execution. The foreign minister Charles Fombrun framed it as continental solidarity. Declarations against Germany and Italy followed within days.
Source
Primary source: US State Department, Foreign Relations of the United States 1941, vol. VI