The US has expelled 12 diplomats from Russia's mission to the UN, saying they engaged in espionage activities , a move which Moscow described as a "hostile action" and gross violation of the commitments by the US as host country of the United Nations headquarters.

US Mission to the United Nations Spokesperson Olivia Dalton said that the US has informed the United Nations and the Russian Permanent Mission to the United Nations that we are beginning the process of expelling twelve intelligence operatives from the Russian Mission who have abused their privileges of residency in the United States by engaging in espionage activities that are adverse to our national security.

"We are taking this action in accordance with the UN Headquarters Agreement. This action has been in development for several months.

Russia's Permanent Representative to the UN Ambassador Vassily Nebenzia was addressing an end of Presidency press conference at the UN Headquarters when he got a telephone call informing him of the expulsion of his diplomats by the US. Russia was President of the 15-nation Security Council for the month of February.

I just received the information that the US authorities have undertaken another hostile action against the Russian mission to the United Nations, grossly violating their commitments under the host country agreement. They told us they are announcing 12 people (UN diplomats) from the personnel of the Russian mission persona non grata and demanding that they leave by March 7, Nebenzia said.

He said the US authorities just visited the Russian mission and gave us a note prescribing us to do what they demand. You know that with the Secretary-General we raised the issue of arbitrage with the host country, which grossly violates its commitments under the host country agreement. So far it has not been done, but I think it's high time already. This is just hot news that I received right away.

When asked who the Russian diplomats were who have been expelled, he said he didn't know the names yet, but that they are 12 in number.

This is sad news and another demonstration of gross disrespect to the host country agreement, to US commitments within the framework of their obligations, both under the UN Charter, the host country agreement and Vienna conventions, Nebenzia said.

When asked if Russia is going to respond to Washington's decision to expel its diplomats, he said I'm sure that the response will follow because it's a diplomatic practice which provides for a tit-for-tat. It's not our choice. We didn't initiate it and I think that the answer will be given but it's not for me to decide.

Nebenzia later raised the issue of the expulsion of his diplomats at the start of the UN Security Council meeting on the humanitarian situation in Ukraine.

Deputy U.S. Representative to the United Nations Ambassador Richard Mills, responding to him, said that the status of the 12 diplomats is not really the proper subject for this meeting, especially given the gravity of what we're here to discuss which is the untold humanitarian suffering in the country of Ukraine.

But since you have raised the issue, I will just assure my colleagues that the step that the United States government informed the Russian mission of today was taken in full accordance with the Headquarters Agreement that we signed with the UN, and that those diplomats that have been asked to leave the United States were engaged in activities that were not in accordance with their responsibilities and obligations as diplomats, Mills said.

Mills added that under Section 13(b) of the Headquarters Agreement, the Russian diplomats have been given a request to depart this country so they do not harm the national security of the host country. And I look forward to taking the issue up where it properly belongs, which is in the Host Country Committee.