UNITED NATIONS, April 14 (Xinhua) -- The United Nations on Monday called a "serious issue" the dispute between the Islamic Republic of Iran and the United States over Tehran's choice for its new ambassador to UN Headquarters in New York and Washington's refusal to issue a visa to him.
It was the first UN comment on the diplomatic row.
Stephan Dujarric, spokesman for UN Secretary-General Ban Ki- moon, was asked at a regular briefing if he had seen published reports that Iran had sent a letter asking for the United Nation's assistance in the dispute.
Iran's Foreign Ministry has said it plans to challenge the U.S. decision at the United Nations, saying the UN-Host Country treaty guarantees issuance of visas for delegates to the world body headquarters.
"We've seen the reports over the last few days and this morning on the Foreign Ministry in Tehran," Dujarric replied. "The short answer, we have not received -- as of five minutes ago when I asked as many people as I could -- we have not received any official letters from the Islamic Republic of Iran. However I know there have been some preliminary phone contacts taken by the permanent mission here with secretariat officials."
"This is a very serious issue that is being raised," the spokesman said. "Things are being taken step by step. As soon as we have more we will share it."
"What we're really waiting for is the official letter from the Islamic Republic, for all intents and purposes we know is coming, we just haven't seen it. Once we have it we will take a look at it -- what its asking of the Secretariat of the United Nations -- and we'll be able to respond and share more information with you," he said.
Tehran had announced Hamid Aboutalebi was chosen to be its new UN ambassador.
However, the White House spokesman Jay Carney said on Friday the United States would not grant a visa to Aboutalebi, allegedly linked to the 1979 revolution and the takeover of the U.S. embassy in Tehran where hostages were held for 444 days.
Last week, U.S. State Department spokeswoman Jen Psaki said the United States still has the right to deny visas to UN diplomats by citing "security, terrorism, and foreign policy" concerns.
No specific reasons were cited by either spokesperson.