The United States must drop its 'cowboy' attitude if it wants to hold dialogue with Iran over its nuclear programme, President Mahmoud Ahmadinejad said on Monday. 'We are for negotiations, but to do so you have to sit down like a good boy,' Ahmadinejad said, referring to the United States, in a speech broadcast live on state television. 'They adopt a resolution to force a dialogue, but this cowboy logic has no place in Iran.' World powers led by the US voted for new UN sanctions against Iran on June 9 in a bid to force it to stop its nuclear programme which they suspect is aimed at making weapons. Iran denies its atomic drive has military aims. Following up on the UN sanctions, US President Barack Obama on July 1 imposed Washington's toughest-ever unilateral punitive measures against Iran. Ahmadinejad said Washington's real concern was not that Iran may make an atom bomb but that Tehran is fast rising as a regional power. 'They say we have intelligence that Iranians will most likely build one atomic bomb. Well, this is a lie, but let's say it is true. How many atomic bombs do you have?' the hardliner said in his speech, delivered in the northern city of Qazvin. 'The Americans themselves say 5,000 plus... Is someone who has 5,000 fourth and fifth generation atomic bombs, with very advanced launchers, afraid of one bomb? They are not afraid of one, not of a hundred, not of a thousand (bombs). They are afraid of the collective awakening of the Iranian soul.' Displaying his trademark defiance, Ahmadinejad vowed that Iran would not back away from its uranium enrichment programme. Washington, he charged, knew full well that Iran is 'not after an atomic bomb,' despite its claims to the contrary. 'You sanction our banks and some products and think that we will back down and hand over the key to the Iranian nation,' he said. 'They should know that they will take their dream of forcing down the Iranian nation to their graves. Our nation is one family... we may have different views, but we are one body against you.' World powers, immediately after the UN sanctions measure was passed, called for dialogue with Iran as part of its dual track strategy of imposing punitive measures and at the same time offering to hold talks. But Ahmadinejad has ordered a freeze in talks at least until end of August as a 'penalty' against world powers for imposing sanctions on Tehran. 