Under a 2015 nuclear deal between Iran and world powers, the Islamic republic shut down the original Arak reactor in Markazi province so that it could not produce military-grade plutonium.

It also pledged that a replacement of the original reactor with a new one would support "peaceful nuclear research".

Quoted on Sunday by the Fars news agency, Mustafa Nakhai, spokesman of the legislature's energy commission, said "the Arak IR-20 reactor will be launched in a year from now".

Nakhai said he was in turn quoting Mohamed Eslami, newly-appointed to head the Iranian Atomic Energy Organisation (AEOI).

He also quoted Eslami as saying the new IR-20 reactor at Arak will feed into the generation of a planned 8,000 MW of nuclear power, to be achieved by the construction of additional reactors, state news agency IRNA reported.

Nuclear chief Eslami also said in mid-September during a site visit to Arak that Iran wanted to establish the long-planned research facility "as quickly as possible".

The AEOI had said early this year that it would cold test the new reactor in the first three months of the Iranian year, which began on March 21.

The 2015 nuclear deal gave Iran sanctions relief in return for tight controls on its nuclear programme, monitored by the UN.

Tehran has gradually rolled back its nuclear commitments since 2019, a year after then US president Donald Trump withdrew from the multilateral deal and began reimposing sanctions.

Talks began in April in Vienna in a bid to bring the US back inside the deal, but the dialogue has been stalled since June, when ultraconservative Ebrahim Raisi was elected as Iran's president.