Two members of Cuba's UN mission asked to leave US
United Nations (Shutterstock)

Two members of Cuba's UN mission were asked to leave the United States after engaging in "activities harmful to US national security," State Department spokeswoman Morgan Ortagus said Thursday.

"We take any & all attempts against the National Security of the U.S. seriously," Ortagus said on Twitter.

"Members of Cuba's UN mission are also restricted to stay in Manhattan," she added.

The announcement came as the United Nations holds its 74th General Assembly in New York.

Ortagus did not provide any more detail on what the two Cubans were accused of or whether they have left the country.