Talks in Moscow between the United Nations Security Council's veto-holding members ended on Tuesday with a failure of the United States to push through its hard line against Iran over its disputed nuclear program. China and Russia repeated their rejection of any proposals to impose sanctions against Tehran.

At the meeting, deputy foreign ministers from the five veto powers as well as Germany failed to come to any agreement over sanctions or any other measures against the mullah state.

Iran claims that it's efforts to enrich uranium are intended exclusively for its civilian nuclear energy program, but many in the international community suspect that the Islamic republic is seeking to build a nuclear bomb that would radically alter the balance of power in the powderkeg Middle East region.

US Undersecretary of State Nicholas Burns said the diplomats had recognized the "need for a stiff response to Iran's flagrant violations of its international responsibilities." He added that the Bush administration would not tolerate the idea or reality of an Iran with nuclear weapons.

In a separate briefing, State Department spokesman Sean McCormack said the countries were all "committed to trying to work together within the Security Council mechanism to find a way to increase the pressure on the Iranian regime so that they will change their behavior."

Meanwhile, US President George W. Bush on Tuesday again expressed his desire to find a diplomatic solution to the nuclear impasse with Tehran. Asked if he would consider a military or nuclear strike on Iran in Washington, Bush told reporters, "all options are on the table." Nevertheless, the president said "we want to solve this issue diplomatically, and we are working hard to do so." The best way to achieve that goal, he said, is by working together with countries "who recognize the danger of Iran having a nuclear weapon. That's why we're working very closely together with countries like France, Germany and Britain." Bush said he would also address Iran in a meeting with Chinese leader Hu Jintao, who is currently visiting Washington.

The Security Council members are expected to hold additional talks in the coming days, and Canada and Italy are also expected to participate in the next round of negotiations, which have so far been limited to the UN veto-holding powers and Germany.

On Tuesday, Iranian President Mahmoud Ahmadinejad warned the West with sharp words against waging war against his country over its disputed nuclear plan. Describing the Iranian army as one of the strongest in the world, he said it would "cut off the hands of any aggressors and will make any aggressor regret it."

Despite Ahmadinejad's saber-rattling, the Iranian government expressed its fundamental willingness to negotiate with the United States. Prior to the meetings in Moscow, Russian Foreign Minister Sergey Lavrov, whose country is building Iran's Bushehr nuclear research laboratory, said the international community should work closer with the International Atomic Energy Organization to resolve the problem.

Last week, Tehran intensified the debate abroad when Ahmadinejad claimed his country is testing an advance P-2 centrifuge that could speed up the country's path towards developing a nuclear weapon. However, IAEA sources said they treated the news with "cautious skepticism," since Ahmadinejad didn't make the statements on radio or television and nobody could confirm whether they had actually been made.

The Security Council has demanded that Iran halt any uranium enrichtment activity by April 28, and Undersecretary of State Burns said he expected the world body to take action if Tehran fails to adhere to the demand.