United Nations - The UN was "very much in touch" with the US government over the visa issues raised by some of its member states, a spokesman for the world body said.

In response to questions regarding Iranian Foreign Minister Mohammed Javad Zarif's failure to get a US visa for a Security Council meeting this week, Stephane Dujarric, spokesman for the UN Secretary-General, on Tuesday stressed the UN's position that the Host Country Agreement should be upheld, reports Xinhua news agency.

"We have made that clear over the last few months where there have been a series of cases," said the spokesman.

Headquartered in New York, the UN is largely seen as an "international realm", but delegates from outside of the US need an American visa to attend its meetings.

Under the 1947 Headquarters Agreement, the US is required to allow foreign diplomats enter the country on UN-related business.