Iran will cold test its redesigned Arak nuclear reactor as a prelude to fully commissioning it later in the year, Iran’s Atomic Energy Organisation said on Friday. Spokesman Behrouz Kamalvandi said the cold testing, which usually includes the initial start-up of fluid systems and support systems, will take place early in the Iranian new year, which begins this Sunday. "In other words, we have advanced work in the field of fuel, storage, etc," Mr Kamalvandi said. Iran recently accelerated its breaches of the 2015 international nuclear deal in an apparent attempt to pressure US President Joe Biden to reverse his predecessor's abandonment of the agreement. Both sides are locked in a stand-off over who should move first to save the deal. Iran agreed to shut down the reactor at Arak – about 250km south-west of Tehran – under the 2015 deal. It was allowed to produce a limited amount of heavy water and Tehran has been working on redesigning the reactor. It says it plans to make isotopes for medical and agricultural use. The International Atomic Energy Agency said in a report to member states earlier this week that Iran has started enriching uranium at its underground Natanz plant with a second type of advanced centrifuge, the IR-4, in a further breach of the deal. Last year Iran started moving three cascades, or clusters, of different advanced models of centrifuge from an above-ground plant at Natanz to its underground fuel enrichment plant. It is already enriching underground with IR-2m centrifuges. The deal allows it to enrich there only with first-generation IR-1 machines. Iran is enriching uranium up to 20 per cent purity at another plant, Fordow.