The head of the International Atomic Energy Agency Mohamed ElBaradei says the action is meant as a "a very serious and ominous message" for Iran to comply with international regulations" and failures in the future will not be tolerated.
Had the issue gone to the Security Council sanctions against Iran could have been levied.
The resolution the IAEA's 35-nation board of governors adopted in Vienna balances the US call to condemn Iran for 18 years of hidden nuclear activities that included making plutonium and Britain, France and Germany's demand that Iran be rewarded for cooperating since October with the IAEA.
ElBaradei said the resolution marked "a good day for peace, multilateralism and non-proliferation".
US demands dropped
In talks that began at the IAEA board last week, the US dropped demands to take Iran immediately before the Security Council for "non-compliance" with the nuclear Non-Proliferation Treaty (NPT). But it had still wanted a guarantee that the Council be alerted if Iran's violations continue.
Iran's representative to the
IAEA Ali Akbar Salehi
Iran, for its part, has sought to reassure Western states it would keep its key promise to sign a protocol allowing intrusive snap inspections of its atomic sites.
"Certainly we have committed ourselves to sign the Additional Protocol and that's what we are going to do," Iran's representative to the UN nuclear watchdog, Ali Akbar Salehi, said. He did not say when the protocol would be signed.
The IAEA resolution contains a so-called trigger clause; if further breaches are uncovered, the IAEA board will meet immediately to consider "all options", one of which is the Security Council.