TEHRAN – Iran was under diplomatic pressure Friday after a UN watchdog report said it had expanded its nuclear program and was hampering inspections, and UN chief Ban Ki-moon in Tehran called on it to release political prisoners. The IAEA report was released late Thursday – in the middle of the summit – and said Iran had doubled its capacity to enrich uranium at its underground Fordo nuclear facility by installing, but not yet switching on, more than 1,000 more centrifuges. It also said that UN inspectors wanting to see part of a military base in Parchin, outside Tehran, which is suspected of hosting tests of explosives that could be used in a nuclear warhead, had been “significantly hampered" by months of refused access. It said there had also been what looked like intensive scrubbing and scraping at the facility, and the use of covers to shield the site from satellite cameras. Iran's uranium enrichment, and its Fordo bunker, were two of the key points raised in negotiations this year by the P5+1 – the UN Security Council's five permanent members plus Germany -- that have all but stalled. EU foreign policy chief Catherine Ashton, representing the P5+1, is to talk with Iran's chief nuclear negotiator Saeed Jalili “in the coming days," Ashton's spokesman said on Thursday. Iranian officials have previously emphasised that Parchin is an off-limits military base and that the IAEA's focus on it is overblown and based on “false" Western intelligence. Ban, in his speech at the Iranian diplomats' college, expanded on criticism of Iran's nuclear stand that he had delivered in meetings with Khamenei and President Mahmoud Ahmadinejad, and at the opening of the summit. – Agencies