WASHINGTON — Twenty-nine Republican senators have written to US President Barack Obama urging him to deny a visa to a former hostage-taker who is Iran’s choice for ambassador to the United Nations.

The senators said Thursday that the United States should not allow entry to an individual who participated in an act of terror against the US and its citizens.

Hamid Aboutalebi was a member of a Muslim student group that stormed the US Embassy in Tehran in 1979 and held 52 Americans hostage for 444 days.

Mark Kirk and Marco Rubio led the senators and said US Ambassador Samantha Power should work closely with the UN to ensure Aboutalebi is denied entry.

The State Department says it was troubled by the selection but stopped short of saying it would refuse a visa.

State Department deputy spokeswoman Marie Harf called the potential nomination of Hamid Aboutalebi “extremely troubling” and said the US has raised its concerns with Tehran. Lawmakers in Congress who usually disagree on everything — ranging from liberal New York Democrat Sen. Chuck Schumer and conservative Texas Republican Sen. Ted Cruz — have demanded that Aboutalebi be barred from living and working in the United States.

But Harf noted that except in limited cases, the US is generally obligated to admit the chosen representatives of member states to UN headquarters in New York.

“We’re taking a close look at the case now, and we’ve raised our serious concerns about this possible nomination with the government of Iran,” Harf told reporters. She added: “But we do take our obligations as host nation for the United Nations very seriously.”

Copyright 2014 The Associated Press.