VIENNA (AP) - The U.S. accused Iran of deception and defiance Wednesday, asserting that over the past decade it has stonewalled international demands to allow scrutiny of its nuclear programs. The European Union was also critical of Iran, as the 35-nation board of the International Atomic Energy Agency focused on the failure of attempts to persuade the Islamic Republic to reduce fears about its nuclear activities. One concern is Tehran's refusal to heed U.N. Security Council demands that it stop uranium enrichment and construction of a reactor that will produce large amounts of plutonium. Both can be used to arm nuclear weapons. The other is the failure of IAEA attempts to restart its investigation of allegations that Iran has worked directly on developing such weapons. That probe has been stalled for more than six years, and 10 rounds of Iran-IAEA negotiations over the past 18 months have failed to revive it. Iran says all of its nuclear programs are peaceful and insists the allegations of weapons work are based on forged intelligence from its enemies. It was expected to respond to the new criticism later in the day. U.S. envoy Joseph Macmanus said the lack of progress "documents Iran's longstanding practice of deception and noncompliance," while an EU statement described Iran's "procrastination" as unacceptable. The EU said it is deeply concerned about Iran's enriched uranium program and a reactor that will produce plutonium when finished. An earlier statement by the U.S. and five other world powers was less forceful, reflecting the sensibilities of China and Russia. While joined with the United States, Britain, France and Germany in trying to negotiate with Iran on its nuclear program, those two nations are traditionally less critical of Tehran for strategic and economic reasons. The six said it is "essential and urgent" that Iran reaches an agreement with the IAEA that will allow the agency to investigate suspicions Iran worked on nuclear weapons. They said IAEA access to Parchin is particularly important. The agency has tried vainly over its 18 months of negotiations to visit the suspected site of weapons-related experiments. Beyond fears that Tehran may have worked on atomic arms, most international concern has focused on its uranium enrichment, because this is further advanced than the reactor and already has the capacity to enrich uranium to weapons-grade. But fears now are growing about the reactor at Arak, in central Iran, which Tehran says will be operational by next year. In a May report, the IAEA noted that Iranian technicians there already had taken delivery of a huge reactor vessel to contain the facility's fuel. It also detailed progress in Tehran's plans to test the fuel. Former IAEA Deputy Director General Olli Heinonen said that with such progress, there is a good possibility that the reactor will have started to operate by the end of 2014. He said Iran had been successful in evading sanctions in importing some components for Arak, while apparently manufacturing others domestically. The IAEA's ability to monitor the reactor to make sure none of its plutonium is being diverted for possible weapons use is another worry. The agency says it has all the means it needs to make sure that does not happen with Iran's enriched uranium, including cameras, physical inspections and seals on certain materials and components. But it complains that Tehran's refusal to provide construction details of the reactor could hamper it in looking for possible proliferation dangers there. Heinonen, the former IAEA official, said the agency can devise proper monitoring methods and equipment at any facility it is supervising only if it sees the blueprints early.