"The Islamic republic of Iran accepted the additional protocol and the Nuclear Non-Proliferation Treaty, but if we see that the European countries do not respect their commitments within the IAEA, naturally we will no longer respect our own commitments," Kamal Kharazi was quoted as saying by the official IRNA news agency.
The International Atomic Energy Agency (IAEA) spent Thursday locked in meetings at its headquarters in Vienna, to discuss a ruling on Iran's nuclear record.
The United States, which accuses Iran of trying to develop nuclear weapons, wants the IAEA to declare Tehran in "non-compliance" with the NPT.
Using the term "non-compliance" is the trigger-word for bringing the issue before the UN Security Council, which could impose sanctions.
"We must wait until tomorrow to see if the Americans have succeeded in their attempts," Kharazi said Thursday.
Britain, France and Germany, which won key concessions of cooperation with the IAEA on a visit made by foreign ministers to Tehran on October 21, want to avoid moves that might scale back further cooperation.
IAEA governors are due to rule Friday whether signatory Iran has violated the NPT by secretly making plutonium and enriched uranium.