U.S. and Iran Take Tough Stances in Standoff

WASHINGTON, April 18 —As diplomats meeting in Moscow failed to reach agreement on how best to raise pressure on Iran over its nuclear program, the American and Iranian presidents, both using tough language, staked out unyielding positions today.

In response to a reporter's question, President Bush declined to rule out a nuclear attack to stop Iran from building atomic weapons if diplomacy fails. "All options are on the table," he said. But Mr. Bush added, "We want to solve this issue diplomatically, and we're working hard to do so."

In Tehran, a defiant President Mahmoud Ahmadinejad told the Iranian military that it had to be "constantly ready," and he warned bluntly that Iran would "cut off the hand of any aggressor," The Associated Press reported.

In Moscow, Undersecretary of State Nicholas Burns said diplomats of the five permanent United Nations Security Council members plus Germany had recognized the "need for a stiff response to Iran's flagrant violations of its international responsibilities," The Associated Press reported.

But he said talks on possible sanctions against Tehran had failed to produce an agreement. Mr. Burns said the United States expected Security Council action if Iran misses an April 28 deadline to stop uranium enrichment.

Neither Mr. Burns nor other American officials would say whether Russia and China had softened their opposition to sanctions.