United States President Barack Obama signed a bill on Friday that bars Iran’s proposed ambassador to the United Nations from legally gaining entry to the US.

One week earlier, White House press secretary Jay Carney confirmed that the Obama administration was opposed to Iran’s request to have Hamid Aboutalebi serve as the Islamic Republic’s ambassador to the UN.

As RT reported previously, Aboutalebi, 56, previously served as Iran’s ambassador to three countries and the European Union, but is perhaps most infamously known in the US for his alleged role within a group, Muslim Students Following the Imam's Line, that occupied the US Embassy in Tehran in 1979 and held dozens of Americans hostage.

Congress earlier this month drafted a bill barring Aboutalebi from entering the US, but such decisions require the approval of the president himself. Amidst pressure from Capitol Hill, Pres. Obama signed a decree doing such on Friday.

The bill, S 2195, “den[ies] admission to the United States to any representative to the United Nations who has been found to have been engaged in espionage activities or a terrorist activity against the United States and poses a threat to United States national security interests.”

Sen. Ted Cruz (R-Texas), the author of the bill, said when he proposed it that Iran’s choice for UN envoy was a “deliberate and unambiguous insult to the United States.”

“Given the larger strategic threats to the United States and our allies, represented by Iran’s nuclear ambitions, this is not the moment for diplomatic niceties,” he said.“I am proud to join my colleagues on both sides of the aisle on this national security issue that transcends political parties.”

The latest efforts out of Washington come on the heels of the first discussions between the American and Iranian heads of states in decades. Last year Pres. Obama and his Iranian counterpart, Hassan Rouhani, spoke over the phone for the first time ever, and afterwards the American leader said "I believe we can reach a comprehensive solution” concerning Iran’s nuclear program. Discussions on the matter were expected to be entertained by the UN, but a dispute over Iran’s choice of envoy may now jeopardize those talks.