Reports say North Korean leader Kim Jong Il is to visit China next week as concerns grow that Pyongyang may soon test a nuclear explosive. China's leaders also plan a meeting with the South Korean president, to discuss ways to bring Pyongyang back to nuclear disarmament talks.

Kim Jong Il shakes hands with Hu Jintao during January 2006 visit to China

News organizations in South Korea and Japan say Kim Jong Il could make a three-day trip to China in the middle of next week.

The visit, if it happens, would come as relations between the historical allies are strained over North Korea's recent missile tests and concerns Pyongyang may soon test a nuclear device.

Yan Xuetong, the director of international studies at China's Tsinghua University, says Mr. Kim wants a security assurance from Beijing or else he will likely go ahead with a nuclear test.

"North Korea wants to know if China and North Korea will or will not continue to keep their military alliance," he said.

Yan indicates it is unlikely China would agree to support Pyongyang militarily. He says no country is now willing to take responsibility for North Korea's behavior.

China supported its communist ally in the early 1950s during the Korean War, which China still calls the "Help North Korea Resist America" war.

However, as China has opened its economy and society to the outside world, North Korea has remained in self-imposed isolation.

China has hosted several rounds of negotiations with Russia, South Korea, the United States, and Japan aimed at convincing North Korea to give up its nuclear weapons programs.

Those talks have been stalled since November. Pyongyang refuses to return to talks until the U.S. removes financial sanctions it imposed for alleged illegal North Korean dealings, including counterfeiting.

Thursday, South Korea confirmed that President Roh Moo-hyun will visit China in October and will discuss ways to end the standoff with Chinese leaders.

Mr. Roh's senior security advisor was traveling to China Thursday for talks on North Korea with Chinese Foreign Minister Li Zhaoxing.

Last week, ABC News in the U.S. reported that North Korea might be preparing to test a nuclear explosive device - as part of its efforts to build nuclear bombs.

South Korea and the United States have warned Pyongyang that doing so would seriously escalate tensions.

In July North Korea defied warnings from its neighbors, including China, and test-fired seven missiles into the sea.

China joined the U.N. Security Council in condemning the launches as a provocation and calling on member states to refrain from contributing to North Korea's weapons programs.