Washington shifted course on Tuesday and said it was willing to talk to North Korea about its atomic program, as the U.N. nuclear watchdog said Pyongyang had "only a matter of weeks" to readmit inspectors expelled last week. The United States, which previously insisted North Korea roll back recent steps to revive its nuclear programs before any talks, announced its new position after holding talks at the State Department with South Korea and Japan.

"The United States is willing to talk to North Korea about how it will meet its obligations to the international community," the three countries said in a joint statement.

"However, the U.S. delegation stressed that the United States will not provide quid pro quos to North Korea to live up to its existing obligations," the statement added.

Earlier, the reclusive communist state intensified its rhetoric, demanding the United States open talks and saying any sanctions over its nuclear program would "mean a war, and the war knows no mercy."

President Bush had hinted at the U.S. change in position on Monday, saying, "We'll have dialogue," without setting any preconditions.

His aides said later North Korea must first dismantle its nuclear weapon programs, a precondition they acknowledged they dropped on Tuesday. "This is a step forward from what we have been saying and doing," one senior U.S. official said.

Tensions have flared since Pyongyang last month expelled U.N. inspectors and vowed to restart a reactor idle since a 1994 pact that froze its nuclear program in exchange for oil from the West.

The U.S. decision marked a partial step in the direction of South Korea, which has argued in favor of a dialogue with the North. In media leaks over the weekend, South Korea dropped hints it wanted Washington to give North Korea security assurances and a promise to resume energy supplies in return for Pyongyang dismantling its nuclear programs.

The United States is seeking to play down the threat from North Korea, which analysts believe may already possess one or two nuclear weapons, as it prepares for a possible war with Iraq, which it also accuses of seeking weapons of mass destruction but which is not believed to possess nuclear weapons.

Speaking in Chicago, Bush, who has branded North Korea part of an "axis of evil" along with Iraq and Iran, sought to allay North Korean anxieties about U.S. intentions by again saying the United States had no intent of invading the country.

"We have no aggressive intent, no argument with the North Korean people. We're interested in peace on the Korean Peninsula," Bush said. "I believe that by working with countries in the region, diplomacy will work."

NUCLEAR WATCHDOG CHALLENGES PYONGYANG

In Geneva, the U.N. International Atomic Energy Agency said time was running out for Pyongyang to comply with demands for resumed oversight of its nuclear facilities.

"We have ... made it very clear to North Korea that it is not an open-ended invitation. It's only a matter of weeks," Mohamed ElBaradei, head of the nuclear watchdog, told CNN.

"If they do not come into compliance, we will have to go to the (U.N.) Security Council and the Security Council will take it from there," he said.

"We are only talking about weeks because I am supposed to report to our member states as a matter of urgency. I interpret urgency to mean weeks at the most," he said.

PHOTO CAPTION

U.S. Secretary of Defense Donald Rumsfeld answers a reporter's question during a briefing at the Pentagon in Washington, January 7, 2003. Rumsfeld echoed President George W. Bush's Monday's statement and said that he remained open to dialogue, but White House officials said the North Korea must first end efforts to develop atomic weapons-a condition US officials admit now they have dropped. REUTERS/William Philpott