"We've been taking it very, very seriously from the beginning, and we will continue to take very seriously the health and safety of all Canadians who serve anywhere overseas", Trudeau said.
He also noted there was "no question that the health impacts on diplomats in Cuba have been visible and real".
The unusual illness was first reported by Canadian Embassy employees in Havana in 2016, with the last confirmed case being in November 2018.
According to the Canadian Foreign Ministry, the diplomats experienced headaches, dizziness and difficulties with concentration. Moreover, the symptoms remained even after some of the embassy staff left Cuba.