U.S. Vice President Kamala Harris departed Singapore more than three hours late on Tuesday because of concerns about "an anomalous health incident” in Hanoi, her next destination, the State Department said.

"Earlier this evening, the vice president’s traveling delegation was delayed from departing Singapore because the vice president’s office was made aware of a report of a recent possible anomalous health incident in Hanoi, Vietnam,” the U.S. Embassy in Hanoi said in a statement. "After careful assessment, the decision was made to continue with the vice president’s trip.”

The State Department has frequently used the phrase "anomalous health incidents” to describe so-called Havana Syndrome, which has afflicted dozens of U.S. diplomats and intelligence officials who describe feeling ill and other unusual physical sensations after hearing strange sounds. The U.S. has not determined a cause for the affliction, and the White House on Tuesday declined to say if the individual’s symptoms were similar to those in other Havana Syndrome cases.