Thu Sep 27, 5:20 PM ET

WASHINGTON - President George W. Bush reached out to China to exert its influence on Myanmar on Thursday, an admission that new U.S. sanctions alone will not be enough to stop the ruling junta's crackdown on protesters.

Trying to rally the international community against Myanmar's generals, Bush met Chinese Foreign Minister Yang Jiechi and asked Beijing "to help bring a peaceful transition to democracy in Burma," the White House said.

The surprise talks came after at least nine people were killed in Myanmar as police and soldiers cleared the streets of central Yangon in a two-day-old crackdown on the country's largest protests in 20 years.

Even as tightened U.S. sanctions went into force on Thursday against Myanmar's military leaders, Bush appeared to acknowledge the limits of Washington's power in the crisis.

"I call on all nations that have influence with the regime to join us in supporting the aspirations of the Burmese people and to tell the Burmese junta to cease using force on its own people who are peacefully expressing their desire for change," Bush said in a written statement.

But he focused his personal diplomacy on China, the closest the isolated junta has to an ally. Beijing is a key trading partner and arms supplier to Myanmar and is seen as the linchpin for any international effort to defuse the situation.

Bush invited Yang to the Oval Office during the Chinese official's previously scheduled White House meeting with national security adviser Stephen Hadley.

He thanked China for helping to win Myanmar's consent to a visit by U.N. envoy Ibrahim Gambari and asked that Beijing "use its influence" with the junta, White House spokesman Gordon Johndroe said.

For its part, China has said it is "extremely concerned" about the situation in Myanmar and has urged restraint by all parties. But it has not given any sign it is willing to go further in pressuring Myanmar's government.

U.S. SANCTIONS

The United States has been pushing for years, to little avail, to get Myanmar to free Nobel laureate and pro-democracy politician Aung San Suu Kyi and has led a campaign of isolation while demanding political reform.

Bush announced new sanctions at the U.N. General Assembly earlier this week, adding to U.S. measures long in effect.

The U.S. Treasury on Thursday said it had targeted 14 Myanmar leaders, prohibiting financial transactions with them and freezing any U.S. assets. It also broadened a U.S. travel ban on Myanmar officials and their families.

"Every civilized nation has a responsibility to stand up for people suffering under a brutal military regime like the one that has ruled Burma for so long," Bush said in Thursday's statement.

The European Union has threatened tougher sanctions but has yet to take action.

"U.S. efforts alone are not enough," said Derek Mitchell, an Asia expert at the Center for Strategic and International Studies. "We shot our bullet on sanctions a long time ago."

He said China may have leverage to convince Myanmar to "take a less aggressive approach," but that the junta won't take orders from Beijing for deeper political reform.

A leading European Parliament lawmaker suggested that European countries should boycott the 2008 Beijing Olympics unless China does more to resolve the Myanmar crisis.

The White House played down any prospect of the United States staying away from the games or Bush canceling plans to attend if China fails to put pressure on Myanmar. But Bush spokeswoman Dana Perino reiterated the president's view the "world is going to be watching" in the run-up to the Olympics.

"He thinks that the Olympics is a time when people can pay attention to a lot of different issues. This would be one of them," she said, referring to the Myanmar situation.