Iranian Foreign Minister Mohammed Javad Zarif attends a press conference in Baghdad, Iraq. File picture: Xinhua

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.

Media reports on Tuesday quoted the Zarif as saying that US Secretary of State Mike Pompeo informed the UN Secretary-General that Washington won't issue the Foreign Minister a visa, citing shortage of time to process the request.

Dujarric confirmed to reporters that the Secretary-General and Pompeo spoke on Monday and "discussed a number of issues", while refusing to disclose any other details.

Asked if the UN plans to raise the issue to the US if the situation remains unchanged, Dujarric said "we remain in, very much in touch with the Department of State".

According to media reports, Zarif applied for a visa on December 20, a day after receiving an invitation from the Security Council to speak at a ministerial meeting on Thursday on Upholding the UN Charter.