The time for negotiation with Iran has ended. No more sanctions, no more inspections -- it's done. washingtonpost.com PITTSBURGH, Sept. 25 -- The government of Iran has told the International Atomic Energy Agency that it is building a previously undisclosed uranium enrichment plant for making fuel, the nuclear watchdog agency said Friday. President Obama will call attention to the existence of the underground facility in an early-morning statement to reporters here before the opening of the G-20 economic summit, and will say that Western intelligence agencies have been tracking the facility for years. U.S. officials said Obama decided to disclose the program's existence after learning that Iran had become aware that it was no longer a secret. Obama's statement, which will be made jointly with the leaders of France and Great Britain, was added to his schedule late Thursday night. It comes a day after Obama chaired a United Nations Security Council session on halting the spread of nuclear weapons throughout the world. Although Obama referred to the nuclear ambitions of both Iran and North Korea during the session, diplomatic maneuvering kept any mention of the two countries out of a resolution that the council unanimously approved. The omission prompted passionate criticism from French President Nicolas Sarkozy, who will join Obama and British Prime Minister Gordon Brown Friday morning to decry Iran's newly disclosed facility.