US President Barack Obama on Saturday offered Iran "a serious, meaningful dialogue" over its disputed nuclear program, while warning Teheran of grave consequences from a united global front.
"Iran's leaders must now choose - they can live up to their responsibilities and achieve integration with the community of nations. Or they will face increased pressure and isolation, and deny opportunity to their own people," Obama said in his weekly radio and Internet address.
Evidence of Iran's building an underground plant to enrich uranium that could be used for an atomic bomb "continues a disturbing pattern of Iranian evasion" that jeopardizes global nonproliferation, the US president said.
Ahead of Thursday's international talks with Iran in Geneva, Obama said the world "is more united than ever before" on this issue. Those negotiations, he said, "now take on added urgency."