Updated

Differences often dominate U.S.-Chinese summits, but Friday's meeting between President Bush and Chinese President Jiang Zemin is expected to be a sober exchange on their shared concerns about a nuclear-armed North Korea.

Both governments say they don't want to see North Korea in the nuclear camp. The big question is whether the two countries can agree on a joint strategy to minimize the threat both believe is posed by the North's newly disclosed weapons program.

Trade, Taiwan, Iraq and human rights all will be on the agenda at Bush's Texas ranch, but North Korea will transcend all other issues.

The two leaders will meet ahead of the Asia Pacific Economic Cooperation conference this weekend in Los Cabos, Mexico.

U.S. officials say China does not want another declared nuclear power on its border, and both the United States and China believe that the North Korean nuclear program, left unchecked, could trigger an arms race in the region.

China was more oblique than the United States in its criticism, asserting last week that it did not support any country that develops weapons of mass destruction.

Jiang, 72, probably will be meeting with Bush for the last time as China's leader since he is expected to make a gradual exit from power in the months ahead. But the Bush administration is not treating him as a lame duck.

China often is billed as North Korea's closest ally, but Beijing has on occasion been at odds with its reclusive neighbor.

After China joined the nuclear club in 1964, North Korean leader Kim Il-sung asked for China's help in developing a nuclear weapons of its own. Chinese leader Mao Zedong said no.

Don Oberdorfer, an Asia expert at the Johns Hopkins School of Advanced International Studies, said China rebuffed North Korea again in 1994 when Pyongyang was suspected of traveling down the nuclear weapons path.

China told North Korea it would not veto proposed sanctions against Pyongyang that were being considered by the U.N. Security Council, Oberdorfer said.

At Friday's meeting in Crawford, Texas, Bush will wonder how far Jiang will be willing to go in pressuring North Korea to reverse course on its nuclear weapons program.

For his part, Jiang will be curious about whether Bush has regime change in mind for North Korea, much as he does for Iraq. Oberdorfer says there is a point beyond which China will not support U.S. policy in North Korea.

"If the Bush administration's goal is regime change, the Chinese would be very much opposed to that,'' he said. "Getting rid of weapons is one thing. Getting rid of regimes is another.''

One difference between Iraq and North Korea is that the latter is much more dependent on outsiders than Iraq.

A new report by the Heritage Foundation says that vulnerability must be exploited.

The United States, Japan and South Korea "should end all food and fuel aid to North Korea immediately'' and encourage Russia and China to do the same until North Korea takes steps to eliminate its nuclear weapons programs, say Heritage researchers Balbina Y. Hwang, Larry M. Wortzel and Baker Spring.

The Bush administration has said it will not allow political considerations to influence food donations because such gifts help needy North Koreans.

U.S.-Chinese relations have been on the upswing, and China has made several friendly gestures toward Washington lately to ensure a friendly visit.

Hoping to deflect criticism of its policy toward Tibet, China has released a Tibetan nun from prison and received a representative of Tibet's exiled Bhuddist leader, the Dalai Lama.

It also has taken several steps over the past two months to ease U.S. concerns about China's proliferation activities on both the nuclear and biological weapons fronts.

Taiwan remains a sore point in the relationship. China continues to make clear its opposition to U.S. arms sales to Taiwan. The Bush administration has criticized Chinese missile deployments across from Taiwan.