President Obama on Friday signed legislation aimed at stopping Hamid Aboutalebi, Iran's would-be U.N. ambassador, from entering the United States.
The bill, offered by Sen. Ted Cruz (R-Texas) and passed unanimously in both chambers of Congress, blocks admittance to the U.S. by representatives to the United Nations determined to have "engaged in terrorist activity" against the U.S. or its allies.
Aboutalebi has admitted that he worked as a translator and negotiator for the student group that held Americans hostage in 1979 at the U.S. Embassy in Iran for 444 days. His nomination drew cries of outrage from lawmakers on both sides of the aisle who accused Tehran of using the nomination as a deliberately provocative act.
The White House announced earlier this month that the administration would not issue a visa to Aboutalebi, but stopped short of saying whether the president would sign the bill.
"Acts of espionage and terrorism against the United States and our allies are unquestionably problems of the utmost gravity, and I share the Congress's concern that individuals who have engaged in such activity may use the cover of diplomacy to gain access to our nation," Obama said.
But the president nevertheless warned the legislation could "interfere" with his discretion to receive or reject ambassadors, a duty explicitly outlined in Article II of the Constitution.
Obama noted that former President George H.W. Bush attached a similar signing statement in 1990 to legislation that barred entry of any U.N. representatives who had engaged in espionage against the United States. In that statement, Bush said "curtailing by statute my constitutional discretion to receive or reject ambassadors is neither a permissible nor a practical solution."
Earlier this week, Iran sent a letter to U.N. Secretary-General Ban Ki-moon asking the international body to review the denial of Aboutalebi's visa.
"This decision of the U.S. government has indeed negative implications for multilateral diplomacy and will create a dangerous precedence and affect adversely the work of intergovernmental organizations and activities of their member states," Deputy U.N. Ambassador Hossein Dehghani wrote, according to Fox News.
But aside from possibly condemning the move by the U.S., the United Nations has little recourse in the matter.
The move from the White House could, however, spark other widespread diplomatic ramifications.
Aboutalebi is a top adviser to Iranian president Hassan Rouhani, and his rejection could scuttle negotiations over the country's weapons programs. Hard-liners within Iran are likely to cite the U.S. rejection of Aboutalebi's visa as evidence that Washington does not abide by the terms of international agreements.
U.S. Ambassador to the U.N. Samantha Power said last weekend that the visa issue had not yet disrupted the nuclear talks.