The United States and other major world powers will hold a special summit next week in Berlin to discuss how to deal with Iran in the standoff over nuclear weapons development, U.S. officials announced Thursday. U.S. Undersecretary of State Nicholas Burns and his counterparts from the United Kingdom, China, France, Germany and Russia will meet in Berlin to discuss which sanctions will be levied on Tehran, State Department spokesman Sean McCormack said. After Iran failed to adhere to a United Nations Security Council deadline Thursday to cease uranium enrichment, the Bush administration and other world leaders must now devise a retaliatory strategy, McCormack said. The Bush administration insists that Iran s uranium enrichment and other nuclear research programs are a cover for developing nuclear weapons. In addition to the summit of major powers, EU foreign policy chief Javier Solana is set to meet with Tehran s main negotiator, Ali Larijani, next week in Berlin as well. McCormack said there was no possibility for direct talks between representatives of the six major powers and the Iranian envoy. There will be diplomatic contacts with the Iranians to encourage them to take the offer that has been made to them and to comply with the just demands of the international community, he said.