Iranian parliament speaker Ali Larijani warned on Sunday that Tehran would review its cooperation with the International Atomic Energy Agency (IAEA) should it face
"unjust" measures.
Larijani's statement come a week after EU powers triggered a dispute mechanism under Tehran's 2015 nuclear deal.
The move by France, Britain and Germany amounts to formally accusing Iran of violating the terms of the deal and could lead eventually to reimposing UN sanctions that were lifted under the pact, Reuters reported.
"We state openly that if the European powers, for any reason, adopt an unfair approach in using the dispute mechanism, we will seriously reconsider our cooperation with the International Atomic Energy Agency," state
TV quoted Larijani as saying.
Earlier last week, Tehran said it would abandon limits on enriching uranium, though it would continue to cooperate with the UN nuclear watchdog.
President Hassan Rouhani has repeatedly said that Tehran's nuclear steps were reversible if Tehran's economy was shielded by other parties to the deal from US penalties.
Under the deal between Iran and major powers, Tehran agreed to curb its nuclear programme in exchange for lifting international sanctions against the Islamic Republic.
The three European nations said they still wanted the 2015 nuclear deal to succeed and were not joining a "maximum pressure" campaign by the US.
Meanwhile, a group of Iranian lawmakers signed a statement on Sunday warning the European powers to "stop their hostile approach" toward Tehran, Iran's semi-official Tasnim news agency reported.
"Otherwise we, as representatives of the Iranian nation, will decide whether Iran should remain in the nuclear deal or whether it should continue its cooperation with the IAEA," the lawmakers said, Reuters reported.
