The United Nations expressed its concerns over recent information revealed by one of the leaked US classified documents that Washington was spying on UN chief Antonio Guterres.

"The UN officially expressed its concern regarding recent reports that the communications of the Secretary-General and other senior UN officials have been the subject of surveillance and interference by the US government," spokesperson Stephane Dujarric said.

Such practices "are inconsistent with the (US) obligations... enumerated in the UN charter and the Convention on the Privileges and Immunities of the United Nations," the spokesperson continued. 

The Washington Post unveiled last week one of the Pentagon's leaked documents stating that the United States spied on at least four of the UN chief's discussions with other officials in the organization.

Commenting on the leak, Guterres stated that he is not surprised about being spied on, as Dujarric revealed last Thursday.

"The Secretary-General... has been in politics and a public figure for quite some time," Dujarric told reporters. "So he is not surprised, I think, by the fact that people are spying on him and listening to his private conversations."

Read more: US allies going berserk over Pentagon intel leak: Politico

As early as March 2, 2023, over 100 intelligence papers were posted on Discord, a social media platform popular with gamers, and appeared to contain highly classified information - originating mainly from Pentagon - on Ukraine, Russian military activity, China, and the Middle East. 

The United States claimed that the source of the leaked US documents is Jack Teixeira, a US Air National Guard member in his early to mid-20s who worked in a military post and is known for his critical views of the US government.

Following the leak of US "Top Secret" documents, CBS News reported on Wednesday that the Pentagon significantly reduced the number of government-employed officials that receive classified information.