From Elise Labott reporting from Paris
U.S. Secretary of State Hillary Clinton lambasted Russia and China on Friday for blocking efforts to topple Syrian President Bashar al-Assad, whose much-reviled regime has endured a serious crack in its armor - the defection of a key member of its inner circle.
Speaking at the Friends of Syria conference in Paris, Clinton called on Russia and China to "get off the sidelines" and accused them of "standing up for" al-Assad's regime. She urged the other 60 or so nations represented at the summit to "make it clear that Russia and China will pay a price" for that support.
"I ask you to reach out to Russia and China and not only ask but demand that they get off the sidelines," she said. "I don't think Russia and China believe they are paying any price at all, nothing at all, for standing with (the) Assad regime."
But it was unclear whether those two nations will reverse their longstanding opposition to forcing al-Assad from power. The two trade partners of Syria have vetoed previous efforts by the U.N. Security Council to condemn the violence in Syria and oust al-Assad. Neither Russia nor China was represented at the Paris meeting.
Western and Arab nations started the Friends of Syria initiative because both countries posed diplomatic obstacles in tackling the Syrian crisis. The United States and others hope this meeting of the group could lead to stricter economic sanctions and more support for the opposition.
Clinton's tough comments came as a Western diplomat confirmed that Manaf Tlas, a general in Syria's elite Republican Guards, abandoned the regime.
Tlas, the son of a former Syrian defense minister, defected over the killing of Sunnis, said the official, who spoke on condition of anonymity. The official was not authorized to speak to the media.
"He's an inside confidant of Assad. So it counts that even an insider thinks it's time to go," the official said.
His father, a former defense minister, and the rest of his family are in Paris, the official said. It was not immediately known if Tlas was on his way to France.
The defection is one more blow for al-Assad, who Clinton said has been feeling the bite of economic sanctions. The Syrian leader's "currency and foreign reserves have collapsed," she said, curbing his ability to continue his crackdown.
But she said challenges remain. Al-Assad was being kept afloat by "money from Iran and assistance from Russia and the failure of countries here" at the conference to tighten economic sanctions.
"None of us is satisfied or comfortable with what is going on in Syria," she said.
But she noted that in the last several months since the Friends of Syria met in Tunis in February, "there has been a steady march toward ending this regime."
The Paris meeting comes less than a week after a conference of foreign ministers, which included China and Russia, met in Geneva, Switzerland, and called for a transitional government body as a step toward ending the Syrian crisis.
That emergency meeting, called by former U.N. Secretary-General Kofi Annan, raised hopes that Russia was easing its position. But even as Russia appeared to agree that a key step in the peace process was the establishment of a transitional government, the country's foreign minister said it should not be viewed as outside powers imposing a transitional government on Syrians.
Senior U.S. officials said the United States and its European and Arab partners will move to impose global sanctions if Syria doesn't quickly implement the transition plan that includes the appointment of a new government.
Diplomats at the United Nations are already working on a document that would demand restrictions on oil and other commercial business with the Syrian regime if it refuses to implement the Annan peace plan for a cease-fire and a transitional government. A Security Council resolution under Chapter 7 of the U.N. Charter could be introduced next week, the officials said.
Chapter 7 could ultimately authorize the use of force.
The officials said the Russian and Chinese willingness to discuss a political transition plan in Syria and sign on to that plan last week in Geneva could boost the effort to impose sanctions. The absence of the two nations at the Paris conference, however, reflects the difficulties ahead in persuading Moscow and Beijing to back the resolution.
Clinton praised the Syrian opposition's six-page "vision" for a Syrian transition, unveiled last week at its meeting in Cairo, Egypt.
The United States hopes the document, which has details on a new parliament and constitution, will allay fears of Alawite and other minority groups that the Sunnis leading the fight against al-Assad will grab all of the power and take revenge on al-Assad's supporters. The regime is dominated by Alawites, an offshoot of Shiite Islam, and the opposition is largely Sunni.
French President François Hollande also called for al-Assad's departure Friday, saying a political transition is the only way to end 16 months of violence in the Middle East nation.
Members of the Syrian opposition attended the Paris meeting, and many are pushing for the imposition of a no-fly zone in Syria.
Riad Seif, a former member of parliament recently allowed to leave Syria to seek medical treatment, made an impassioned plea at the meeting.
"After so many conferences, we fail to see how we have so many friends and people are dying every day," Seif said. "We would like your friendship to be effective, to put an end to this massacre."
At least nine people were killed in fighting early Friday, according to the opposition Local Coordination Committees of Syria. Among the dead, the LCC said, were six in hard-hit Idlib, a flashpoint in the uprising that began in March 2011 and has left thousands dead. Those deaths follows reports that at least 70 people were killed Thursday, the LCC said.
CNN cannot independently confirm reports of violence or casualties as Syria has limited access by international journalists.
CNN's Ben Brumfield and Chelsea Carter contributed to this report.