UNITED NATIONS - The UN Secretariat has received the US decision to expel 12 diplomats of the Russian mission to the world body, said a UN spokesman on Monday.

"I can confirm that the United States mission to the United Nations informed the Secretariat of its decision to take action under Section 13 (b) of the UN-US Headquarters Agreement with respect to certain members of the Permanent Mission of the Russian Federation to the United Nations. This action may require those members to leave the country (of the United States)," said Farhan Haq, deputy spokesman of UN Secretary-General Antonio Guterres.

"Given the sensitivity of the matter, which is ongoing, we will not comment further at this stage other than to confirm that the secretary-general will closely follow this matter and engage, as appropriate, with the governments concerned," Haq told a daily press briefing.

He refused to answer any questions that would involve any detail of the matter, including whether the United Nations has been given the names of the 12 diplomats to be expelled.

Washington has announced the expulsion of 60 Russian diplomats, including 12 from the Russian UN mission in New York, as well as the closure of the Russian Consulate-General in Seattle.

The US action is said to show solidarity with its ally Britain, which claims that Moscow is responsible for the poisoning of a former Russian spy on March 4 in Britain with a military-grade nerve agent. Russia has denied involvement in the case.

Britain has announced the expulsion of 23 Russian diplomats after the poisoning of Sergei Skripal, 66, and his daughter Julia in the southern English city of Salisbury.

US ambassador to the United Nations Nikki Haley said Monday that her country has begun the process of "expelling 12 intelligence operatives from the Russian Mission to the United Nations who have abused their privilege of residence in the United States."

"After a review, we have determined that the 12 intelligence operatives engaged in espionage activities that are adverse to our national security. Our actions are consistent with the United Nations Headquarters Agreement," said Haley in a press statement.

Section 13 (b) of the 1947 UN-US agreement on the UN Headquarters in New York reads: "In case of abuse of such privileges of residence by any such person in activities in the United States outside his official capacity, it is understood that the privileges referred to in Section 11 shall not be construed to grant him exemption from the laws and regulations of the United States regarding the continued residence of aliens."

"No proceedings shall be instituted under such laws or regulations to require any such person to leave the United States except with the prior approval of the Secretary of State of the United States. Such approval shall be given only after consultation with the appropriate Member in the case of a representative of a Member (or a member of his family) or with the Secretary-General or the principal executive officer of the appropriate specialized agency in the case of any other person referred to in Section 11," it reads.