A State Department spokesperson said the agency “is aware of this incident and is currently investigating the matter.”

Authorities are investigating a ploy in which an impostor used AI to impersonate Secretary of State Marco Rubio to contact three foreign ministers, a U.S. governor and a member of Congress.

The fraudulent messages were sent via text, encrypted messaging app Signal, and voice mail, and suggest a broader effort to deceive recipients into believing they were communicating directly with Sec...