The US President Barack Obama on Friday called upon Iran to abandon its nuclear weapons programme and cooperate with IAEA and the UN Security Council for transparency with meaningful dialogue. <br/><br/>In a strongly worded statement, minutes before the start of the G-20 meeting in Pittsburgh the US president said that Iran is breaking all rules that all nations must observe; international law is not an empty promise and the treaty will be enforced. <br/><br/>Flanked by President Sarkozy of France and the British Prime Minister, Mr Gordon Brown , the US President said that evidence had been given to IAEA demonstrating that Iran is building a covert enrichment facility and expect the Agency to investigate.<br/><br/><br/>President Sarkozy of France called upon Iran to abandon any military ambition for its nuclear programme and said further and more stringent sanctions will be imposed if Iran does not engage with the international community as a partner. The British Prime Minister, Mr Gordon Brown also endorsed the view and said stricter sanctions will be invoked.<br/><br/>The US President said that the German Chancellor Angela Markel who was not present during the press statement also associates with the views expressed by the three leaders. <br/>