TEHRAN: Iranian President Mahmoud Ahmadinejad today warned that world powers would regret any moves to slap new sanctions on Iran, while stressing Tehran was still ready for a UN-brokered nuclear fuel exchange deal. “If anybody seeks to create problems for Iran, our response will not be like before,” the hardline Iranian president told a packed news conference in the capital Tehran. “Something in response will be done which will make them (the world powers) regret” their move, he said. Ahmadinejad said negotiations over a UN-drafted nuclear fuel exchange were “not closed yet,” and expressed readiness to buy the material even from Iran’s arch-foe the United States. Last year the International Atomic Energy Agency proposed sending Iranian low-enriched uranium (LEU) abroad for further enrichment, denying Tehran refining capacity powers fear could be used to help build an atomic bomb. The offer would have seen the uranium returned to Iran in a high grade form for use in a Tehran medical research reactor, but the plan has been rejected by the Islamic republic. Ahmadinejad today insisted that the exchange had to be “simultaneous,” a stance repeated by several other Iranian officials and which has led to a deadlock over the deal. “The proposal for the fuel exchange is not closed yet. We have announced that we will exchange within a just framework,” Ahmadinejad said. “We are ready for an exchange even with the United States. The US can come and give us their 20 percent fuel and we will pay them if they want, or we can give them 3.5 percent fuel. “But the swap should take place simultaneously and we will put our fuel under the supervision of the (UN atomic) agency in Iran,” he added without clarifying whether the exchange must take place inside the country as insisted by other Iranian officials. Ahmadinejad also indicated Tehran could suspend enriching uranium to the 20 percent level if world powers supplied it the required fuel for Tehran reactor. “We are not insisting on doing this (20 percent enrichment) although we have the capability. If they supplied the (uranium enriched to) 20 percent, the situation may change,” he said in answer to a question if Iran would stop the enrichment started last week. Iran announced on February 9 that it had begun work on enriching the uranium to 20 percent level.