Iran warned on Tuesday against a potential resolution at the UN nuclear watchdog condemning its suspension of some nuclear inspections, but stressed it remains committed to diplomacy.

Britain, France and Germany, the three European members of the 2015 Iran nuclear deal, will put forward the resolution during this week's meeting of the International Atomic Energy Agency's board of governors, according to diplomatic sources.

A document circulated by the Iranian mission in Vienna and seen by AFP said such a resolution would effectively end the temporary agreement that IAEA chief Rafael Grossi worked out with Tehran to mitigate what he calls the "huge loss” of some inspections.

"I have to give this warning, that actions against our expectations will have adverse effects on diplomatic processes, and can quickly close the windows of opportunity,” Iran’s government spokesman Ali Rabiei told reporters.

Iran expects "all parties to act rationally and prudently, and to know the value of fleeting moments”, he added. "We are still committed to diplomacy.”

Restrictions on inspections went into force on February 23.

It followed a law passed by the Iranian parliament in December, that called for suspending certain commitments if the US does not lift unilateral sanctions or the three European countries do not help Tehran to bypass those sanctions.

Under the agreement with the IAEA, that runs for up to three months, data from cameras on Iran’s nuclear programme will be stored and not handed over to the agency, and if sanctions are not lifted by that time, Tehran will start erasing the recordings.

According to Rabiei, the agreement conveyed Iran’s "goodwill”, and now the Islamic republic expects other parties to the nuclear deal to "prove” theirs.

Diplomatic sources in Vienna say the European resolution is expected to face a vote on Friday, and that it is backed by the United States.

The 2015 landmark nuclear deal has been hanging by a thread since former US president Donald Trump withdrew Washington from it and reimposed punishing sanctions on Iran in 2018.

Current US President Joe Biden has signalled his readiness to revive the deal, but insists Iran first return to all its nuclear commitments, most of which it suspended in response to the sanctions.

Tehran demands Washington take the first step by scrapping the sanctions.

Iran on Sunday dismissed a European offer for an informal meeting involving the US on the deal, saying the time is not right as Washington has failed to lift sanctions.