But underscoring international mistrust of Pyongyang's erratic leaders, Washington insisted UN sanctions imposed on North Korea after it carried out its first nuclear test explosion on October 9 would remain in force for now.
"We'll be sending teams to the region to work with our partners to make sure that the current United Nations Security Council resolution is enforced," Bush said, adding that he was "very pleased" with North Korea's apparent about-face.
The United States announced earlier on Tuesday that North Korea had agreed during talks in Beijing to return to six-party negotiations on abandoning its nuclear program which Pyongyang had been boycotting for a year.
After seven hours of talks with US envoy Christopher Hill, the North Koreans also promised to abide by a September 2005 pledge to give up its nuclear arsenal, believed to include up to a dozen bombs.
The breakthrough came barely two weeks after the UN Security Council voted unanimously to impose wide-ranging sanctions on North Korea designed to starve its military of funds and materiel needed for its arms programs and to prevent Pyongyang from selling its weapons know-how to terrorists or other states.
It also followed a whirlwind tour of the region by US Secretary of State Condoleezza Rice, who obtained strong assurances from the Chinese that they would implement sanctions against North Korea embodied in UN Security Council resolution 1718.
Bush attributed the surprise breakthrough to the US policy of dealing with North Korea through a coalition of regional states rather than resuming bilateral negotiations which had failed in the past to halt Pyongyang's nuclear program.
"I've always felt like it is important for the United States to be at the table with other partners when it comes time to addressing this important issue," he said.
North Korea had been demanding bilateral talks with the US as a condition for returning to the broader negotiations that also involved China, Japan, Russia and South Korea, and Bush has been under growing pressure from across the US political spectrum to engage the North directly.
But he held firm in insisting that only a multi-party process, notably involving China -- North Korea's long-time ally and principle aid and trade partner -- could convince bring the fellow communist regime to heel.
Bush and other US officials stressed that despite Tuesday's agreement, the UN sanctions should remain in place until North Korea, which has broken numerous past deals, takes further steps in giving up its weapons.
"Obviously, we've still got a lot of work to do," Bush said. "There's no letting up," added State Department spokesman Sean McCormack.
"Implementation of 1718 continues forward and it will continue to be implemented until the Security Council decides otherwise and individual countries decide otherwise," he said.
McCormack said the goal was "complete, irreversible and verifiable de-nuclearisation" of North Korea, though he declined to present these terms as preconditions for lifting the sanctions.
The six-party talks began in 2003 with the intent of convincing North Korea to give up its nuclear ambitions.
In September 2005, North Korea said it would renounce all nuclear weapons and programs, return to the international Non-Proliferation Treaty and allow UN weapons inspectors back into the country.
The other countries, in turn, agreed to "respect" the North's demand for peaceful nuclear energy and said Pyongyang's request to have a light-water reactor for peaceful purposes would be revisited "at an appropriate time."
But Pyongyang walked away from the discussions after the United States slapped sanctions on a Macau-based bank, Banco Delta Asia, suspected of money laundering and passing counterfeit US dollars on behalf of North Korea.
Hill said the future of the action against Banco Delta Asia would be discussed at the six-party talks.

Copyright AFP (Agence France-Presse), 2006