The United States appeared to violate one of the most basic tenets of the United Nations by refusing to issue a visa to Iran's top diplomat who was to address the Security Council this week.

An anonymous US official confirmed the move to the Reuters news agency.  Although Iranian Foreign Minister Mohammad Javad Zarif requested the visa "a few weeks ago" to address the importance of upholding the UN charter, the Trump administration denied the visa amid rising tensions between the two countries following the United States assassination of Iran's top military commander Major General Qassem Soleimani, in an airstrike in Baghdad last Friday.  

The Iranian government made the request and was awaiting the US response; instead, US Secretary of State Mike Pompeo informed Secretary-General Antonio Guterres the visa was denied.  The Trump administration claims it can deny diplomatic visas for "security, terrorism and foreign policy" reasons.

But as the host of the United Nations in New York, Trump and Pompeo violated the terms of the 1947 headquarters agreement which requires Washington to allow foreign officials into the country to carry out UN business.  

"Any foreign minister is entitled to address the Security Council at any time and the United States is obligated to provide access to the UN headquarters district," said Larry Johnson, a former United Nations assistant secretary-general, in an interview with Foreign Policy Magazine.  He said that under the terms of the US agreement with the United Nations "they are absolutely obligated to let him in".

Mr. Zarif went to the UN three times in 2019, with Pompeo putting increased limitations on his movements with each visit - mostly to keep Zarif, a skilled debater with numerous US media contacts, from making the rounds of the network newsrooms and giving interviews to express Tehran's viewpoints.