Iran asked the UN on Tuesday to demand that the United States grant a visa to Tehran's proposed new UN envoy, while Washington stood firm on its decision to deny entry to Hamid Abutalebi over his suspected links to hostage-takers.

The US has said it would not grant a visa to Abutalebi because of his connection to the 1979-1981 Tehran hostage crisis when Iranian students seized the US Embassy and held 52 Americans hostage for 444 days. Abutalebi has said he acted only as a translator.

The UN Committee on Relations with the Host Country, which deals with the issues of states operating in the United States such as immigration, security, banking and parking violations, met on Tuesday at Iran's request to discuss the matter.

"We firmly believe that this is a very serious issue and the committee should address it in an urgent and serious way," Iran's Deputy UN Ambassador Hossein Dehghani told the panel.

Washington's denial of a visa for Abutalebi was "so obviously" a breach of a 1947 "headquarters agreement" between the United States and the UN that "the committee should deal with it in an extraordinary way," Dehghani said.

Under the pact, the US is generally required to allow access to the UN for foreign diplomats.

Washington has said it can deny visas for "security, terrorism, and foreign policy" reasons.

A 1947 Joint Resolution of Congress said nothing should be seen as "diminishing, abridging, or weakening the right of the US to safeguard its own security and completely control the entrance of aliens" into any part of the US aside from the UN headquarters.

The 19-member Committee on Relations with the Host Country could ask UN lawyers for an opinion to establish if there is a dispute between the UN and the US on the issue.

The pact says disputes should be referred to a tribunal of three arbitrators, one each chosen by the UN and the US and the third agreed by both or appointed by the president of the International Court of Justice.

"We believe that the Secretary-General of the United Nations, who represents one party to the bilateral treaty of headquarters agreement, has a responsibility to shoulder and has to work towards ensuring that the terms and provisions of the agreement are strictly observed," Dehghani said.

Reuters