Iran's UN mission spokesman Hamid Babaei called the decision to bar Hamid Aboutalebi "regrettable", but did not specify any action Tehran might take.
The US accuses Mr Aboutalebi of links to the group that seized the US embassy in 1979, an incident that soured ties between the two countries for decades.
Mr Aboutalebi says he only acted as a translator for the group.
Congress passed a bill last week that would allow the US to refuse an ambassadorial selection if the candidate posed a security risk.
This type of issue will only become more common, as US foreign policy and intervention ratchets up the tension between the US and other nations. So, is the US becoming unviable as a place in which to locate an organisation dedicated to world diplomacy?
The US Congress appears to be caught between US isolationism and engagement with the rest of the world, with the former ruling the roost at present.
While many Americans might indeed welcome any decision to relocate the UN's headquarters, such a move would deal a severe blow to the US's prestige, and thus it's capacity to influence other nations via diplomacy. This prestige is something many other nations would covet and their hosting of the UN's headquarters at the US's expense would be a major coup.
This is not to say such a move is very likely, and this latest spat will certainly ease with time, but the US Congress is doing itself no international favours with it's "patriotism", designed purely for domestic consumption.
Edited by Leonardo, 12 April 2014 - 09:01 AM.