The leaders of the United States, France and Britain say Iran must come clean about its nuclear program, or face consequences from the international community. They joined in a show of unity following revelations Iran has been building a second uranium enrichment plant and has been hiding it for some time.
American, French and British intelligence agencies have been monitoring the site for years. U.S. President Barack Obama says it is clearly not for peaceful purposes. "Iran has a right to peaceful nuclear power that meets the energy needs of its people. But the size and configuration of this facility is inconsistent with a peaceful program," he said.
U.S. Officials say Iran disclosed the site on Monday to the UN atomic watchdog agency - the IAEA - when it discovered the secrecy had been breached.
The IAEA has launched an investigation. British Prime Minister Gordon Brown said Iran must comply. "Confronted with the serial deception of many years, the international community has no choice today but to draw a line in the sand," he said.
French President Nicolas Sarkozy said time is running out for Tehran. "If by December, there is not an in-depth change by the Iranian leaders, sanctions will have to be taken," he said.
The three spoke just moments before the Group of Twenty Economic Summit convened Friday in Pittsburgh. The Iranian crisis overshadowed this gathering of leading and emerging economies, much as it did deliberations earlier this week at the United Nations.
Russian President Dmitri Medvedev learned of the intelligence findings during a private meeting with President Obama on the sidelines of the UN General Assembly.
Both Russia and China have backed the call for an investigation into the uranium enrichment facility. But from Iranian President Mahmoud Ahmadinejad the only response has been a denial of any wrongdoing.
At a news conference in New York, he said Tehran followed rules set down in the Nuclear Non Proliferation Treaty and by the IAEA (International Atomic Energy Agency). "We are operating within the NPT framework and within the framework of the IAEA and that is how we will advance our operations," he said.
The United States and the other world powers actively trying to resolve the Iranian nuclear dispute are scheduled to meet with Tehran's envoys next week in Geneva.
At a press conference closing the G-20 summit, President Obama said Tehran will find the world is united like never before. "What has changed is that the international community, I think, has spoken. It is up to Iran to respond," he said.
The president said he would not speculate on the course of action he might take if diplomacy fails. He said he wants to give the October first talks a chance to succeed.