VIENNA (Reuters) - Iran has complied with a deadline set by its landmark nuclear deal with world powers by removing hundreds of centrifuges, machines that enrich uranium, from a site buried deep inside a mountain, the U.N. atomic agency said on Monday.

U.S. Secretary of State John Kerry shakes hands with Iranian Foreign Minister Mohammad Javad Zarif after the International Atomic Energy Agency (IAEA) verified that Iran has met all conditions under the nuclear deal, in Vienna January 16, 2016. REUTERS/Kevin Lamarque

The deal reached between six powers and Iran in 2015 stated that no more enrichment would take place at the Fordow site near the holy city of Qom for 15 years, but that Iran could keep just over 1,000 centrifuges there for other uses.

Monday’s announcement by the International Atomic Energy Agency (IAEA) will be welcome news to many diplomats who are wondering how U.S. President-elect Donald Trump, a vocal critic of the deal, would handle any problems that might arise.

The transfer of centrifuges and other equipment from Fordow to storage at another underground enrichment site at Natanz was completed within a deadline of one year from the day the deal was put in place, Jan. 16 of last year, the IAEA said.

“Iran has removed excess centrifuges and infrastructure from the Fordow Fuel Enrichment Plant in line with its nuclear-related commitments under the Joint Comprehensive Plan of Action (JCPOA),” the IAEA said in a statement, using the deal’s full name.

The IAEA, which is policing the restrictions the deal placed on Iran’s nuclear activities, verified on Sunday that the move had been completed, the statement added.

With Trump’s inauguration due on Friday, officials who follow Iran closely have said they are waiting to see what stance Trump takes on the deal, which also lifted international sanctions against the Islamic Republic.

Trump has called the agreement, one of the Obama administration’s flagship achievements, “the worst deal ever negotiated”. He has, however, backed away from the assertion that he wants to “rip up” the deal, saying more recently that he would “police that contract so tough they (the Iranians) don’t have a chance.”

That raises the question of how he would react if Iran continued to test the deal’s boundaries. Twice since the pact was implemented in January Tehran has gone over a 130-tonne limit on its stock of heavy water, prompting limited criticism from the United States.

Iran has also argued that the United States has failed to provide the full sanctions relief called for by the deal, a charge Washington denies. Tehran has, however, stopped short of triggering a dispute-resolution mechanism created by the deal.