Q+A: Will U.S. bring China around on North Korea?

WASHINGTON (Reuters) - When U.S. officials accused North Korea in 2002 of mounting a clandestine program aimed at developing nuclear weapons, they urged China to try to rein in the impoverished, secretive state.

Eight years and two North Korean nuclear tests later, U.S. officials are once again beseeching Beijing to bring Pyongyang to heel following disclosures of its sophisticated uranium enrichment program and its shelling of a South Korean island.

While Washington may have a bit more leverage with Beijing this time around, it remains unclear if China is ready or able to restrain its belligerent ally.

WHY IS THE UNITED STATES TURNING TO CHINA?

U.S. influence over North Korea is limited. There are few plausible military options and the United States has extensive and overlapping sanctions against Pyongyang that drastically restrict trade with it.

In contrast, China -- the closest thing to a friend and benefactor that North Korea has -- is believed to account for about half the North's imports and a third of its exports.

Chinese aid and investment have helped North Korea weather repeated rounds of U.N. sanctions imposed over its nuclear and missile tests since 2006.

"China is pivotal to moving North Korea in a fundamentally different direction," U.S. State Department spokesman P.J. Crowley told reporters on Wednesday.

"We do believe that China has influence with North Korea," he added. "We don't want to understate or overstate that. It's not that China can dictate a particular action to North Korea.

"It is that China, together with the United States and other countries, have to send a clear, direct, unified message that it is North Korea that has to change," Crowley added.

WHAT LEVERAGE DOES THE U.S. HAVE THIS TIME?

Chinese President Hu Jintao is expected to visit the United States in January and Chinese officials have made no secret of their desire that the visit be a success.

And while China's economy is burgeoning, surpassing Japan as the world's second largest by some accounts, it has suffered a series of diplomatic setbacks this year and its behavior is increasingly seen as bullying by others in Asia.

As a result, there is growing world pressure on Beijing to assume the responsibilities of its new power and to behave in ways that promote regional and global stability, rather than simply pursuing its own interest.

Increasingly vocal U.S. economic complaints about China, including charges it artificially undervalues its currency to gain trade benefits, may also make Beijing less eager to pick a fight with Washington over the North Korea issue.

WILL U.S. ENTREATIES WORK?

Not likely, analysts say, given Chinese sensitivity about the stability of its unpredictable neighbor at a time when North Korean leader Kim Jong-il is trying to establish his little-known youngest son, Kim Jong-un, as his heir apparent.

Unlike other countries in the region, China has not singled out North Korea for condemnation of Tuesday's shelling of the island of Yeonpyeong, killing two South Korean soldiers and civilians.

Instead, it urged "calm and restraint," called on the two Koreas to enter talks to avoid an escalation of tensions and voiced "pain and regret at the loss of life and property."

Jack Pritchard, president of the Korea Economic Institute in Washington, said Chinese scholars told him China would react even more mildly to fresh North Korean belligerence than it did to the North's alleged sinking of a South Korean warship in March, killing 46 South Korean sailors.

While Beijing may be discomfited by U.S. complaints about North Korea, it is still unlikely to take any action which might result in a cascading political or economic meltdown for its neighbor.

"They are very concerned about the stability and the long-term survivability of the regime," he said.

(Editing by Jackie Frank)