The United Nations has officially expressed concern to the United States over reports of U.S. spying on UN Secretary-General Antonio Guterres and other senior UN officials, UN spokesman Stephane Dujarric said on Tuesday.

"We have made it clear that such actions are inconsistent with the obligations of the United States as enumerated in the Charter of the United Nations and the convention on the privileges and immunities of the United Nations," Dujarric said.