European nations Thursday dropped a planned resolution at the UN nuclear watchdog criticising Iran, in a bid to hasten the revival of the 2015 nuclear deal that was praised both by Tehran and Washington.

France, Britain and Germany -- known as the E3 -- had planned to introduce a resolution at this week's meeting of the International Atomic Energy Agency's board of governors, with the support of the United States, denouncing Iran's suspension of some IAEA inspections.

"We have decided to not present the resolution," the German foreign ministry said.

"Iran must now prove that it is serious in its wish to fully relaunch" the nuclear deal," it added.

One diplomat pointed to initiatives undertaken by IAEA Director General Rafael Grossi and signs of "good faith" on the Iranian side to explain the decision to drop the resolution, which had not been formally submitted.

Grossi announced earlier Thursday that Iran had agreed to hold a series of meetings with the UN nuclear watchdog to "clarify a number of outstanding issues".

US President Joe Biden has said he is willing to bring the United States back to the landmark 2015 deal, known as the JCPOA.

It has been unravelling since Donald Trump pulled the United States out of the agreement in 2018.

A French diplomat said "encouraging signs" from the Iranians would not have been achieved "if the threat of the resolution hadn't been maintained until the end."

The diplomat said it was hoped that a meeting proposed by the EU of the remaining 2015 participants -- Iran, France, Germany, Russia, China and Britain -- could take place within two weeks, with Brussels the likely venue.

Iran welcomed the European decision not to go ahead with a resolution.

"Today's developments can keep open the path of diplomacy initiated by Iran and the IAEA," Iranian foreign ministry spokesman Saeed Khatibzadeh said.

IAEA chief Rafael Grossi said Iran had agreed to some meetings with the UN nuclear watchdog
IAEA chief Rafael Grossi said Iran had agreed to some meetings with the UN nuclear watchdog AFP / ALEX HALADA

"Iran hopes the parties participating in the agreement can seize this opportunity, with serious cooperation, to ensure the full implementation of the agreement by all," he added.

Iran has previously said the time was not suitable for a proposed European-led meeting of all parties including the United States, calling instead for Biden first to lift sanctions imposed by Trump.

In Washington, State Department spokesman Ned Price said the United States was "pleased" with the European move in Vienna and remained ready for dialogue.

"We will look forward with strong interest for Iran's willingness to engage in a way that leads to credible, concrete progress," Price told reporters.

Russia and China also hailed the news, with Moscow's Ambassador to the IAEA Mikhail Ulyanov saying the resolution "could have led to uncontrolled escalation".

Grossi said "a technical meeting" will take place in Iran at the beginning of April as part of a new process aimed at clarifying queries the IAEA has raised about the possible previous presence of nuclear material at undeclared sites.

He said it was his "intention to try to come to a satisfactory outcome for all of this in time for the next regular session of the board of governors" in June.

Earlier this week a report in the Iranian Vatan-e-Emrouz newspaper also said Tehran had temporarily suspended the production of uranium metal on the order of the President Hassan Rouhani.

The JCPOA put a 15-year ban on uranium metal production in Iran but Tehran says it has the right to breach this and a series of other JCPOA limits in retaliation for the US withdrawal from the accord and subsequent imposition of sanctions.

Late last month Iran suspended some IAEA inspections as US sanctions remained in effect.

The suspension was described by Grossi as a "huge loss" for the agency.

However, after two days of talks between Grossi and Iranian officials in Tehran, a three-month arrangement was agreed under which Iran pledged to keep recordings "of some activities and monitoring equipment" and hand them over to the IAEA as and when US sanctions are lifted.

Iran had threatened to suspend that temporary arrangement in the event of a critical resolution at the IAEA.