The trove of leaked classified documents, numbering hundreds of pages and resulting in the arrest of a U.S. air national guardsman on charges of disclosing classified national defense information without authorization, has seen the United States scramble to assess the damage and restrict access to classified information for certain employees at the Department of Defense.

WASHINGTON, April 18 (Xinhua) -- The United States eavesdropped on conversations of the United Nations Secretary-General Antonio Guterres and other UN officials, according to a report by The Washington Post citing leaked classified intelligence documents the newspaper obtained.

Guterres expressed to UN officials and world leaders his "outrage" over being denied an opportunity to visit Ethiopia's war-torn Tigray region, The Post said in a Monday report, citing four documents, two of them previously unreported.

Guterres, according to one dated Feb. 17 and seen by The Post, wanted to confront Ethiopian UN Representative Taye Atske Selassie Amde as the country's foreign minister, Demeke Mekonnen, sent Guterres a letter rejecting his planned visit to Tigray amid peace negotiations.

Another document obtained by The Post revealed that Guterres was "not happy" about having to travel to Kiev to meet Ukrainian President Volodymyr Zelensky in early March. While the document didn't provide a reason for the secretary general's unwillingness, The Post cited a UN diplomat as saying weeks of tiring international travels on commercial flights was the cause.

The trove of leaked classified documents, numbering hundreds of pages and resulting in the arrest of a U.S. air national guardsman on charges of disclosing classified national defense information without authorization, has seen the United States scramble to assess the damage and restrict access to classified information for certain employees at the Department of Defense.

Other documents recently reported by U.S. media showed the United States has also been spying on allies such as South Korea, Israel and Ukraine.

Asked by Xinhua at a Brookings Institution event on Monday to comment on allegations of U.S. spying efforts and on how Washington should soothe the concerns expressed by its allies, Democratic House Representative Abigail Spanberger refused to comment on "anything specifically that was leaked."

The congresswoman, who prior to becoming a lawmaker worked as an operations officer at the Central Intelligence Agency, praised the U.S. administration's "commitment to safeguarding the information that we collect and our commitment to safeguarding the information (U.S. allies) collect and provide to us."