Iranian President Hassan Rouhani speaks at a press conference in Tehran, Iran, on Oct. 14, 2019. (Xinhua/Ahmad Halabisaz)

 
Iran's parliamentary speaker on Sunday warned of unspecified repercussions for the UN's nuclear watchdog if European nations that launched a dispute mechanism against the Islamic republic act "unfairly."

Britain, France and Germany launched a process last week charging Iran with failing to ­observe the terms of the 2015 deal curtailing its nuclear program, while Tehran accuses the bloc of inaction over US sanctions.

The EU three insisted they remained committed to the agreement, which has already been severely undermined by the US exit from it in 2018 and its reimposition of unilateral sanctions on key sectors of Iran's economy.

"What the three European countries did regarding Iran's nuclear issue... is unfortunate," parliamentary speaker Ali Larijani was quoted as saying by state news agency IRNA.

"We clearly announce that if Europe, for any reason, uses Article 37 of the nuclear agreement unfairly, then Iran will make a serious decision regarding cooperation with the agency," he said, referring to the International Atomic Energy Agency (IAEA).

Since May 2019, Iran has progressively scaled back some commitments under the agreement in response to the US sanctions and Europe's inability to circumvent them.

It has stressed, however, that they can be reversed if Tehran's interests are realized.

The 2015 nuclear deal - known as the JCPOA (Joint Comprehensive Plan of Action) - was struck in Vienna by Iran, the EU three, the US, China and Russia.