U.S. officials say Secretary of State Rex Tillerson is to meet with Cuba’s foreign minister amid an ongoing probe into mysterious “attacks” on American diplomats in Havana.

Tuesday’s meeting will also follow a speech the foreign minister delivered at the United Nations last week in which he harshly criticized President Donald Trump and his administration’s policy toward the communist island.

At least 21 U.S. diplomats have suffered physical symptoms, including brain damage and hearing loss, since late last year as a result of what Tillerson has described as “health attacks.” U.S. officials believe that the attacks may have been carried out with some sort of sonic device but have been unable to determine the cause or who is behind them. Cuba has denied any knowledge or involvement.

(AP)