In a reversal of his former hard-line policy, President Bush announced Thursday that he would lift trade sanctions that have been in place against North Korea for more than 20 years. He will also notify Congress the country he once included in "the axis of evil" will be removed from the list of nations sponsoring terrorism in 45 days.

The diplomatic move came after North Korea delivered to Chinese officials documents revealing some of its nuclear weapons activities.

The exchange was another step in a policy turnaround that began in early 2007 when the White House abandoned its former stance of negotiating with North Korea only through multilateral, six-party talks and began direct, bilateral negotiations with the North.

At the same time, the administration gave up on its insistence that North Korea had to dismantle its nuclear program and submit to international inspections before the United States would provide U.S. economic assistance.

Until then little progress had been made while North Korea pursued nuclear testing resulting in an underground nuclear test in October 2006.

The new policy led to an agreement in February 2007 that established a step-by-step process through which North Korea would receive gradual U.S. assistance as reward for adhering to a timeline of actions leading to dismantling of its nuclear facilities.

As part of that pact, North Korea Thursday turned over information about its nuclear facilities and the administration followed by lifting sanctions punishing North Korea for its involvement in the 1987 bombing of a South Korean airliner that killed 115 people.

While hailing the North's move, administration officials cautioned against too much optimism or trust of what Secretary of State Condoleezza Rice called "the most secretive and opaque regime on the planet."

President Bush and Secretary Rice stressed the need to monitor the North's compliance with the agreement and cooperation in denuclearization. Mr. Bush also noted that North Korea remains under international financial and diplomatic sanctions.

The actions, though, come in the middle of a presidential campaign in which the leading candidates disagree over the wisdom of negotiating with hostile nations such as Iran. Republican Sen. John McCain opposes such talks while Sen. Barack Obama, the Democratic candidate, has expressed willingness to meet with the Iranians. But the North Korea talks have shown that engaging hostile nations in negotiations can be more effective than isolation.