UNITED NATIONS - Iran's president is accusing 'a few bullying powers' of trying to thwart the country's nuclear program.

In a speech before the UN General Assembly today, Iranian President Mahmoud Ahmadinejad also declared that 'the American empire' is nearing collapse.

The United States and its allies allege Iran wants to develop its uranium enrichment program to make nuclear weapons.

Iran insists its nuclear program is purely peaceful and designed to produce electricity for civilian use.

Iran already is under three sets of sanctions by the UN Security Council for refusing to suspend uranium enrichment.

Washington and its western allies are pushing for quick passage of a fourth set of sanctions to underline the international community's resolve.