(CNN) -- Iran has named a member of the radical student group that seized the U.S. embassy in Tehran and held Americans hostage for more than a year to be its next ambassador to the United Nations.
Hamid Aboutalebi, was a member of the Muslim Students Following the Imam's Line, the group of militants who seized the U.S. embassy on November 4, 1979, holding 52 Americans hostage for 444 days.
A U.S. official said the State Department has not yet responded to Aboutalebi's visa application to represent Iran at the United Nations.
Aboutalebi is a veteran diplomat who has served as Iran's ambassador to Australia, Belgium, Italy, and the European Union. He has also held high-profile posts in the Iranian Foreign Ministry.
He currently works in the political affairs office of President Hassan Rouhani and is believed to be close to the Iranian leader, who is widely viewed as a moderate with a reformist agenda.
But the choice of Aboutalebi could complicate President Barack Obama's efforts to re-engage with Tehran after the election of Rouhani and negotiate a comprehensive agreement to curb Iran's nuclear program with five other world powers.
With no formal relations between the United States and Iran, the Iranian mission to the United Nations is Tehran's only diplomatic operation in the United States and has played a role in facilitating unofficial exchanges of messages between the two nations.
In an interview with Iranian media, Aboutalebi said he served as translator and negotiator, but denied taking part in the initial occupation of the embassy.
State Department spokeswoman Marie Harf declined to comment if the United States was aware that Aboutalebi was a member of the group which seized the embassy.
She said the United States has a process to review all visa applications, but the applications themselves remained confidential.
"Anyone can submit a visa application, and it will be evaluated as we do all visa applications, in accordance with our procedures," she said. "We don't speculate on what the outcome might be."
But the controversy, first reported this weekend by Bloomberg, could spark demands from Congress to deny Aboutalebi's visa.
That would be an unusual step given the United States is obligated to grant entry visas to representatives of U.N. member-states in accordance with a 1947 agreement signed with the world body.
Last year, Sudanese President Omar al-Bashir decided not to attend the U.N. General Assembly when the State Department failed to respond to his visa application.
The International Criminal Court has issued warrants for Bashir's arrest and referral for trial in the Hague for crimes against humanity.
Although the United States is not a party to the court, the ICC has asked the United States to surrender him if he enters American territory.
Even if the United State granted Aboutalebi a visa, he would not be free to move about the United States. As a representative of a country listed as a State Sponsor of Terrorism by the State Department, Aboutalebi would be confined to a radius of 25 miles from Manhattan, just as diplomats from North Korea and Syria are.
Still, former American hostage Barry Rosen said it would be a "disgrace" if Washington gave a visa to Aboutalebi and called on the Obama administration to deny his application.
"It may be a precedent but if the President and the Congress don't condemn this act by the Islamic Republic, then our captivity and suffering for 444 days at the hands of Iran was for nothing," he said in a statement. "He can never set foot on American soil."