US President George Bush warned Friday that if Iran goes forward with its nuclear program, it might pose a "grave threat to the security of the world." After a meeting with German Chancellor Angela Merkel at the White House, Bush voiced his concern over Iran's decision to pursue uranium enrichment and used the same language he used before launching the American attack against Iraq. The US president stressed that Israel was in most danger from Iran's nuclear developments. When referring to Iranian President Mahmoud Ahmadinejad's call to "wipe Israel off the map," Bush said that "the development of a nuclear weapon, it seems to me, would make them a step closer to achieving that objective." Merkel, in her first visit to the US since elected to lead Germany, agreed with the tough line presented by the US concerning Iran, and joined the call for referring the Iranian nuclear issue to the UN Security Council. The US has already gained the support of the EU for the referral, and Russia has tended to support this move as well. US diplomacy is focused now on China, who is a permanent member of the Security Council and holds the right to veto any decision brought to the forum. Iran supplies China with over 300,000 barrels of oil a day, making it a valuable contributor to the Chinese economy. In his public appearance Friday, Bush was careful not to specify what moves he expected the Security Council to take against Iran, leaving that decision to the members themselves. "I'm not going to prejudge what the United Nations Security Council should do," Bush said, "but I recognize that it's logical that a country which has rejected diplomatic entreaties be sent to the United Nations Security Council." Over the past week the US has been conducting intense diplomatic negotiations with its European allies, mapping out the possible scenarios for a Security Council discussion on Iran. It is clear to the US that the initial stage will include a call to resume inspections, but will probably fall short of mentioning sanctions. These may only be introduced in a second round, after Iran is given time to respond to the demands it was presented. Meanwhile, Ahmadinejad on Saturday shrugged off threats of UN sanctions from Washington and its European allies, saying he would not be bullied because there was no legal basis to forbid Teheran from conducting nuclear research. In a ringing defense of Iran's resumption Tuesday of research at its nuclear enrichment facility at Natanz, Ahmadinejad said Teheran had not violated the Nuclear Nonproliferation Treaty, which he said allowed signatories to produce nuclear fuel. The move drew fierce international condemnation and threats to seek UN sanctions. "The time of using language of bullying and coercion... is over," Ahmadinejad told a packed news conference in the capital. "There is no evidence to prove Iran's diversion (toward nuclear weapons)." What's more, Ahmadinejad said, Iran has no use for nuclear weapons. "You can use nuclear technology in several ways, and we want to do so peacefully," he said, claiming that such weaponry violated the tenets of Islam. Iran insists its program is intended only for electricity generation; the US and other countries fear the explanation is a cover for building a nuclear bomb. The news conference marked the second day of a tough public relations offensive by Teheran. On Friday, Iran threatened to end surprise inspections by and cooperation with the International Atomic Energy Agency (IAEA), the UN nuclear watchdog, if it is referred to the Security Council for possible imposition of sanctions. "The world public opinion knows that Iran has not violated the Nonproliferation Treaty," Ahmadinejad said. "There are no restrictions for nuclear research activities under the NPT protocol, and Iran has not accepted any obligation (not to carry out research). How is it possible to prevent the scientific development of a nation?" Ahmadinejad said there was no reason Iran should not develop its nuclear technology and charged that the threats of sanctions and Security Council action were the true dangers to world stability, not Iran's nuclear program. "We don't trust their (Western countries) sincerity at all. It's certain for us that they don't want the Iranian nation to achieve scientific progress. They openly say 'we are opposed to (Iran's nuclear) research,'" Ahmadinejad said. "On what basis do you say this? Isn't this a medieval mentality? "I'm recommending these countries not isolate themselves more among the people of the world. Resorting to the language of coercion is over." Ahmadinejad said Iran was the victim of "propaganda" and that the presence of IAEA surveillance equipment was proof Iran had nothing to hide. AP contributed to this report.