The United States should tackle the North Korean nuclear issue without expecting China to dump its communist neighbor, an American expert said as Washington has been working hard to enlist Beijing's support for punishing Pyongyang for its fourth nuclear test.

"U.S. thinking about North Korea policy must begin here: China will not take North Korea off life support," Robert Daly, director of the Kissinger Institute on China and the United States at the Wilson Center, said in an article on the think tank's website.

China shares Washington's goal of a denuclearized Korean Peninsula, but it worries that sanctions harsh enough to destabilize the Kim Jong-un regime would send a flood of refugees into northeast China and could bring South Korea's vibrant democracy and its powerful ally, the United States, to China's doorstep, Daly said.

Dumping the North could also cause problems with China's own stability, he said, adding that the legitimacy of China's Communist Party depends on the "history and mythology of the founding of the People's Republic in 1949."

"In Beijing's telling, ideological affinity and alliance with Pyongyang allowed Mao Zedong's upstart nation to defeat the most powerful country on earth in the Korean War. That story has fueled Chinese propaganda for 65 years," Daly said.

"Take away the story by abandoning Pyongyang, and Chinese may wonder what the Party is and why it is still in power," he said.

"Chinese President Xi Jinping won't throw Kim Jong-un under the bus, no matter how much contempt he feels for him."

The expert said the U.S. should plan a two-track approach of continuing to consult and act closely with China whenever possible while at the same time also considering actions that Beijing does not approve of, but cannot prevent, such as penalizing Chinese and international banks that do business in North Korea and deploying enhanced strategic assets in northeast Asia.

Daly said, however, that China is right in advocating dialogue.

"Whenever a crisis occurs, Washington is determined not to 'reward' Pyongyang's bad behavior by negotiating. It is past time to cut that Gordian Knot," he said. "We don't talk to Pyongyang for Pyongyang's sake; we do it for ourselves and our allies, in the service of our security."

U.S. Secretary of State John Kerry is scheduled to visit Beijing on Wednesday on a mission to persuade China to take tough measures to punish Pyongyang for its nuclear test.

China has condemned the North's nuclear test, but has been lukewarm about calls for stern responses. Analysts have long said that Beijing fears pushing Pyongyang too hard could lead to its collapse, instability on its border and ultimately the emergence of a pro-U.S. nation next door.

Chinese cooperation is key to putting together any meaningful punishment as it is one of the five veto-holding permanent members of the U.N. Security Council and the main provider of food and fuel for the impoverished North. (Yonhap)