BEIRUT, Lebanon -- Violence flared across Syria on Sunday, as government warplanes and artillery intensified attacks on rebels in the suburbs east and south of Damascus, fighting closed the highway to the Dara'a in the south, and clashes continued in Homs Province, in central Syria, and in the city of Deir al-Zour in the east, according to state news media and antigovernment activists.
The fierce fighting and desperate living conditions have sent 30,000 Syrians fleeing to Jordan in the past month, with thousands more entering Lebanon and massing on the border with Turkey -- accelerating a flow that now totals 650,000 people who have fled and another 2 million displaced inside the country. The relief effort is underfinanced and overwhelmed, and the United Nations is seeking increased international aid.
The chaos worsened ahead of meetings on the crisis scheduled for Monday, when the main exile opposition group and its international backers are to convene in Paris, and civilian opposition leaders, including some who oppose the use of force, plan a conference in Geneva on building Syrian civil society.
More than 60,000 people have died in the nearly two-year-old conflict, but international efforts to end the crisis appear stalled. The opposition is divided, and Russia, the main backer of Syria's president, Bashar al-Assad, is at loggerheads with the Syrian opposition's Western and Arab supporters.
Russia's prime minister, Dmitri A. Medvedev, told CNN that Mr. Assad's chances of remaining in office seemed to be getting "smaller and smaller" with each passing day, according to a transcript released by Mr. Medvedev's office on Sunday. But he reiterated Russia's insistence that Mr. Assad's ouster could not be a precondition for talks, as the American-backed Syrian opposition leaders have demanded.
Mr. Medvedev said the United States, Europe and regional powers must "sit the parties down for negotiations, and not just demand that Assad go and then be executed" like Libya's ousted leader, Col. Muammar el-Qaddafi, "or be carried to court sessions on a stretcher like Hosni Mubarak," the deposed Egyptian president.
If Mr. Assad is to step down, "this must be decided by the Syrian people," he said, "not Russia, not the United States, not any other country."
Russia's adamant stance against foreign intervention rests on its strategic priority of not allowing precedents to be set that could lead to international action against Russia.
Syrian rebels have pleaded with foreign nations to supply heavy weapons and antiaircraft missiles that they say could turn the tide of the conflict. Some rebel leaders have expressed anger in recent days that Western countries have contemplated aiding France in its attacks on fighters linked to Al Qaeda in the West African nation of Mali while continuing to hesitate on Syria, despite the nearly two years of carnage.
President Obama, in an interview with the magazine The New Republic, signaled his continuing doubts about getting involved in Syria, suggesting no dramatic change would be forthcoming at Monday's meeting.
"In a situation like Syria, I have to ask, can we make a difference in that situation?" Mr. Obama said. "Would a military intervention have an impact? How would it affect our ability to support troops who are still in Afghanistan? What would be the aftermath of our involvement on the ground? Could it trigger even worse violence or the use of chemical weapons? What offers the best prospect of a stable post-Assad regime?
"And how do I weigh tens of thousands who've been killed in Syria versus the tens of thousands who are currently being killed in the Congo? Those are not simple questions."
Fighting edged into a new area of Damascus, the capital, according to activists who said rebels attacked a railway station in the district of Qadam, in the city's southwest. Video posted on the Internet showed gunmen walking near buildings by a railroad track and black smoke that activists said was from an airstrike. The claims were impossible to verify because of the government's restrictions on journalists inside Syria.
This article originally appeared in The New York Times.