The United States, France and Britain have presented "detailed evidence" to the U.N.'s nuclear watchdog that "Iran has been building a covert uranium enrichment facility," President Obama said Friday.
President Obama told Iran to "take concrete steps" to show it will comply with nuclear regulations.
Obama, British Prime Minister Gordon Brown and French President Nicolas Sarkozy -- all in Pittsburgh, Pennsylvania, for a G-20 economic summit -- accused Iran of intentionally hiding its nuclear facilities from the International Atomic Energy Agency.
They threatened a stiff response if Iran fails to conform to international obligations regarding nuclear development.
Iran's newly unveiled uranium enrichment facility "is inconsistent with a peaceful (nuclear) program," Obama said. "Iran is breaking rules that all nations must follow."
