“That really has got to be a serious question, as to whether or not the State Department gives … a visa to him,” Democratic Senator Robert Menendez, chairman of the Senate Foreign Relations Committee, told Reuters.

President Hassan Rouhani has chosen Hamid Abutalebi, a veteran diplomat seen as a moderate, to be Iran’s new ambassador to the United Nations.

People who know Abutalebi said he was part of the Muslim Student Followers of the Imam’s Line, which occupied the U.S. Embassy in Tehran in November 1979, although not among the core group of student activists inside the embassy who captured and held the hostages.

Reports of his ties to the crisis infuriated lawmakers, many of them hardliners who said they reinforced doubts about prospects for negotiations between Iran and world powers over Tehran’s disputed nuclear program.

“We shouldn’t accept him. We should change our rules or laws if we have to so that somebody who is guilty of that kind of behavior should not be allowed in the United States of America,” said Arizona Republican Senator John McCain, a frequent critic of President Barack Obama’s foreign policy.

EX-HOSTAGES ANGRY

Lawyers for former U.S. embassy workers held in Iran for 444 days said on Monday the ex-hostages were angry about Abutalebi’s nomination and wanted him barred from New York.

Republican Texas Senator Ted Cruz introduced legislation that would change U.S. law to allow the country to bar someone who had “committed overt acts of war against the United States” from entering the country.

“This nomination is willfully, deliberately insulting and contemptuous,” Cruz said in a speech in the Senate chamber.

The United States, which severed diplomatic ties with Iran during the hostage crisis, is required to allow U.N. diplomats to come to New York under its host country agreement. It does, however, reserve the right to refuse visas to those seeking to work as diplomats at the world body’s headquarters in New York.

Since Rouhani took office in August, Washington and Tehran have taken tentative steps toward improving relations, above all through high-level bilateral negotiations on the sidelines of talks on Iran’s nuclear program between Tehran and major world powers. Obama and Rouhani spoke by telephone in September.

Many of the lawmakers who spoke out over Abutalebi are among those most skeptical about prospects for any fruitful negotiations with Iran.

Illinois Republican Senator Mark Kirk said he thought the administration should bar Abutalebi and that he would lobby other senators to back him.

Kirk co-sponsored a bill with Menendez seeking to impose tougher sanctions against Iran during the negotiations, despite the Obama administration’s insistence that such legislation could prompt Tehran, and other negotiating countries, to walk away from the talks