U.S. President Barack Obama
U.S. President Barack ObamaFlash 90

29 Republican senators wrote to President Barack Obama on Thursday, urging him to deny a visa to a former hostage-taker who is Iran’s choice for ambassador to the United Nations.

According to The Associated Press (AP), the senators said that the United States should not allow entry to an individual who participated in an act of terror against the U.S. and its citizens.

The Iranian government applied this week for a U.S. visa for Hamid Aboutalebi, Iran’s former ambassador to Belgium and Italy, who was a member of the Muslim Students Following the Imam’s Line, a group of radical students that seized the U.S. embassy on November 4, 1979, and held its staff hostage for 444 days.

Aboutalebi has said he had minimal involvement in the hostage-taking group.

Senators Mark Kirk and Marco Rubio led the senators who asked Obama to deny the visa, and said that Ambassador Samantha Power should work closely with the UN to ensure Aboutalebi is denied entry.

On Wednesday, State Department spokeswoman Marie Harf said that Iran's nomination of Aboutalebi is "extremely troubling".

"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," said Harf.

Also on Wednesday, Senator Ted Cruz said he would introduce legislation to block Iran's application for a visa for Aboutalebi.

"It is unconscionable that in the name of international diplomatic protocol, the United States would be forced to host a foreign national who showed a brutal disregard of the status of diplomats when they were stationed in his country," Cruz said.

"This person is an acknowledged terrorist," he added.

The legislation would require Obama to deny a visa to any UN applicant determined to have engaged in terrorist activity.