US President George W. Bush said Wednesday that his first choice is to solve a nuclear standoff with Iran by using diplomacy, but "all options are on the table." The president reinforced the possibility of a military strike against Iran, even as a last resort, during a news conference with German Chancellor Angela Merkel. Bush warned that a nuclear-armed Iran would be a danger to world peace, and he is rallying European allies to back sanctions. Bush said, "I told the chancellor my first choice, of course, is to solve this diplomatically." He quickly added, "all options are on the table." The president is pushing Iran to halt its uranium enrichment in a verifiable way. Iran insists it is enriching only for peaceful purposes. Merkel said if Iran does not agree to suspend its enrichment program, additional sanctions would be needed. "The offer has been put on the table to Iran, but ... if Iran does not meet its commitments, then further sanctions will simply have to follow," she said. "We again said we want to give room for diplomatic solutions, we want to give diplomacy a chance, but we also have to stay on that particular issue." She said the global community is unified, and that UN sanctions have been effective, and that its important that all of the existing sanctions are implemented. Earlier on Wednesday, Iranian President Mahmoud Ahmadinejad said on Wednesday that Bush's era "has come to an end" and he has failed in his goals to attack Iran and stop its nuclear program. Ahmadinejad, addressing thousands of people in a central Iranian city, also described the US president as "wicked." "This wicked man desires to harm the Iranian nation. (Bush) made plans, moved into Afghanistan and then Iraq, and announced that Iran was the third target," he said. "I tell him (Bush) ... your era has come to an end. With the grace of God, you won't be able to harm even one centimeter of the sacred land of Iran," he said. Ahmadinejad said pressures and sanctions won't succeed in forcing Iran to halt its uranium enrichment program. "In the past two-three years, they employed all their might, resorted to propaganda ... and sanctions. If the enemy thinks they can break the Iranian nation with pressure, they are wrong ... With God's help, today we have achieved victory and the enemies cannot do a damned thing," he said. Meanwhile, in an interview with the London Times which was published on Wednesday, Bush said that Teheran could "either face isolation, or they can have better relations with all of us." During the interview, Bush expressed concern that Democratic presidential candidate Barack Obama would deviate from the current hard-line policy against the Islamic regime. He voiced confidence, however, that once the next president took office and assessed the situation, he would understand "what will work or what won't work in dealing with Iran", and would adopt the same tough stance. Responding directly to comments made last week by Transportation Minister Shaul Mofaz that an attack against Iran was "unavoidable," the president said that "we ought to work together, keep focused. His comments really should be viewed as the need to continue to keep pressuring Iran."