The Iranian president, Mahmoud Ahmadinejad, said Wednesday that his nation would produce a higher grade of nuclear fuel on its own, escalating its war of words with the international community over its disputed nuclear program. His declaration continued a daily drumbeat of defiant proclamations from the Iranian leadership, which has vowed to expand its nuclear facilities and hone its capabilities to enrich uranium despite strong warnings from the United Nations and Western powers that its program violates its commitments under the Nuclear Nonproliferation Treaty. 'I declare here that, with the grace of God, the Iranian nation will produce 20 percent fuel and anything it needs itself,' Ahmadinejad told a cheering crowd in the central city of Isfahan, according to the Reuters news agency. Iran claims it needs a relatively high grade of nuclear fuel for civilian uses. But many in the West suspect its program is aimed ultimately at producing atom bombs. Uranium enriched to 20 percent can fuel a reactor and also marks the dividing line between what nuclear specialists call low-enriched uranium and high-enriched uranium. At the 20 percent level, Iran could, in theory, make an extremely crude and heavy nuclear weapon. The bigger threat would be that its enrichment could quickly accelerate from there to the much higher grade of fuel -- enriched to 90 percent -- typically used in modern nuclear warheads. Iran has said the 20 percent uranium is needed for a reactor in Tehran that produces medical isotopes. The country denies that it has any intention of developing nuclear arms, and Ahmadinejad has not threatened to turn its current stockpile of enriched uranium into bomb fuel. But his new declaration came just days after Iran angrily rejected demands that it shut down a once-secret enrichment plant, and instead vowed to build ten more. Ahmadinejad also announced that his cabinet would study what Iran needed to enrich its existing stockpile of uranium. Over the past two months, the United States and its Western allies have offered to supply uranium enriched to 20 percent for the Tehran medical reactor, but only if Iran shipped some of its current stockpile of low-enriched uranium out of the country. The deal, brokered by the United Nations with support from the United States, sought to defuse tensions surrounding Iran's program. Iran, with uranium enriched to 20 percent in the form of fuel rods for a reactor, would then presumably have no cause for enriching more uranium on its own. But Iran effectively rejected the offer, calling it a ploy by the West to confiscate its existing stockpile. 