They wouldn't make a written statement, but the Pacific Rim's often-divergent leaders joined together Sunday to say they're worried about North Korea's nuclear weapons program and to urge the reclusive country to resume negotiations on dropping it.

The verbal statement capped five days of intensive diplomatic discussions in the aftermath of the North's first nuclear test on Oct. 9, which sparked concerns about proliferation in the region. But the method of delivery provided a curious culmination to the issue that overshadowed the economic topics that are the core of the 21-member Asia-Pacific Economic Cooperation forum's mission.

Even some of the participants weren't sure why the statement wasn't issued in written form, just orally at the end of the two-day leaders' summit and by Vietnam's president at a news conference after reporters asked him about it.

"We are seeking an explanation for that," Canadian Prime Minister Stephen Harper said. "We don't understand why it wasn't included since it was a joint statement and it was unanimous."

U.S. National Security Council official David McCormick denied that getting only an oral statement from the summit represented a setback, and said the White House was pleased with the toughness of the wording.

"The statement was very firm in the need for full implementation" of U.N. resolutions on North Korea, McCormick said. "What was important was that the members of APEC came together on a common statement."

The statement urged North Korea to take concrete steps to live up to earlier commitments to stop developing atomic bombs.

"We express our strong concern over the July 4-5 missile launches and Oct. 9 nuclear test conducted by (North Korea), which poses a clear threat to our shared interest of peace and security and our shared goal of achieving a nuclear weapons-free Korean peninsula," it said.

It appeared that some APEC members, worried about how security and political issues have increasingly impinged on the group's economic focus, didn't want the statement in the final leaders' declaration, feeling that the U.N. and other forums are more appropriate.

And while North Korea is not an APEC member, some countries are sensitive to the issue of interfering in other nations' affairs.

APEC provided a chance for the U.S., China, Japan, Russia and South Korea to try to work out a unified strategy as they prepare to resume nuclear negotiations with the North a year after it walked out. The talks could resume as early as next month.

U.S. President George W. Bush and Chinese President Hu Jintao met Sunday and agreed that "North Korea should get the message that possessing a nuclear bomb will not have the support of the international community, but rather will meet opposition," said Chinese Foreign Ministry spokesman Liu Jianchao.

While virtually everyone agrees that North Korea's first nuclear weapon and missile tests could lead down a dangerous path to further proliferation, differences remain on the best strategy for dealing with the North, which has used brinksmanship to gain aid and security guarantees. Officials talked of a carrots-and-sticks approach.

"I don't think North Korea would want to give up something they regard as something precious to them, something that gives them a certain pride and position," Malaysian Prime Minister Abdullah Ahmad Badawi said.

"These are realities that we cannot deny, but if we can give them hope of something else they can get ... maybe it could pave a way to come up with a solution, but it's going to be very difficult."

U.S. nuclear envoy Christopher Hill is going from Hanoi to Beijing as an apparent follow-up to the discussions here, according to a diplomat from one of the five countries involved in the negotiations with the North, speaking on condition of anonymity due to the sensitive nature of the issue. China has been hosting the six-party talks.

White House press secretary Tony Snow, who flew with Bush to Ho Chi Minh city after the summit, said Hill's trip, said Hill was going to Beijing on Monday.

Asked by reporters what North Korea needs to do to show its commitment to the negotiations, he said there were more players involved than Washington.

"The United States is not the only partner. Everyone has agreed that North Korea (needs to) demonstrate seriousness. The Chinese obviously have been talking, and will continue to talk, and we will continue to talk," Snow said.

It appeared that the U.S. did manage to get one North Korea-related addition in the summit's final written declaration which appeared to endorse the financial sanctions that Washington imposed on the North over alleged currency counterfeiting and money laundering. The sanctions sparked North Korea's boycott of the six-party talks.