VIENNA - On the heels of last week's Iranian nuclear talks in Kazakhstan both the US and the EU voiced their concerns about the Islamic Republic's nuclear program at the board meeting of the UN International Atomic Energy Agency on Wednesday. The US warned Iran that it faces further international isolation and pressure if it fails to address concerns about its nuclear program."We are deeply concerned with what appears to be Iran's unwavering commitment to deception, defiance, and delay," said the US Ambassador to the IAEA Joseph Macmanus.Western countries fear Iran is enriching uranium to develop the capacity to build nuclear weapons and have led several rounds of international sanctions.The EU also voiced deep concern about Tehran's nuclear work and said the Iranian stonewalling of the IAEA's inquiry into suspected atom bomb research was "unacceptable."The 27-nation bloc's joint statement said Iran must suspend its uranium enrichment work, something Tehran has repeatedly ruled out doing.Diplomats said Sweden had tried to weaken the tone of the EU statement, delaying internal approval of the text, which was read out at the closed-door board session later than expected.The revised version said the IAEA's latest report on Iran, which said Tehran was installing more advanced enrichment centrifuges, gave "cause for serious concern." It had initially said the report was "dismal reading," one envoy said.The EU said there was a worrying lack of progress in a long-stalled IAEA investigation aimed at clarifying possible military dimensions to Iran's nuclear program.Western diplomats accuse Iran of preventing progress in the investigation, refusing IAEA requests to visit the Parchin military site where inspectors suspect explosives tests relevant for nuclear arms development took place, possibly a decade ago.Iran denies this, as well as Western allegations that it is seeking to develop the capability to make atomic bombs."The EU considers ... Iran's procrastination to be unacceptable," the statement said.Three EU states - Germany, France, Britain - are part of a group of six world powers that last week resumed talks with Iran in Almaty, Kazakhstan aimed at finding a diplomatic settlement to a decade-old dispute that could trigger a new Middle East war. The other three are the US, China and Russia.