President Barack Obama had come under strong pressure from the U.S. Congress not to allow Hamid Abutalebi into the country. White House spokesman Jay Carney said the United Nations andIran had been told “that we will not issue a visa to Mr. Abutalebi.”

The decision effectively bars Abutalebi of taking up the U.N. position.

The announcement came a day after the U.S. House of Representatives joined the Senate in voting to bar the Iranian from entering the United States.

The legislation, which would need President Barack Obama’s signature to become law, would deny admission of anyone as a representative to the United Nations who has engaged in terrorist activity against the United States.

“We concur with the Congress and share the intent of the bill,” said Carney.

The U.S. government objects to Abutalebi because of his suspected participation in a Muslim student group that held 52 Americans hostage for 444 days starting in 1979, when the group seized the U.S. Embassy in Tehran, the Iranian capital.

After hearing about the former hostages’ anger over Abutalebi, members of Congress jumped to pass legislation banning him, seeing the issue as a chance to look tough on Iran weeks after a new sanctions bill stalled in the Senate. Bills passed unanimously in both chambers this week in a rare show of partisanship.

“We have been very clear with the Iranians that this nomination was not viable,” State Department spokeswoman Jen Psaki said at a regular briefing.

However, the move prompted some concerns.

One congressional staffer said it could set a precedent for U.S. politicians or interest groups to pressure presidents to deny visas for political reasons. It could also prompt visa fights in other countries where international organizations have headquarters, according to the staffer, who requested anonymity to speak freely on the controversial issue.

The United Nations had said it hoped the issue could be resolved bilaterally. Iran has said that, “It has been a usual practice in the Iranian Foreign Ministry to formally appoint Ambassadors for all foreign postings, once all formalities pertaining to this process are completed.”

The United Nations and the Iranian mission to the United Nations did not immediately respond to requests for comment on the U.S. decision.