BEIRUT — Russia said Saturday that there was disagreement over who should represent the opposition in a Syrian peace process, only days after Moscow and Washington announced a joint effort to bring government and rebels to an international conference.
The dispute bodes ill for a civil war in which more than 70,000 people, mostly civilians, have died, and that has left foreign powers looking increasingly helpless.
A senior Kremlin official who attended talks on Friday between President Vladimir Putin and British Prime Minister David Cameron said it would be impossible to meet a target of holding the conference by the end of May.
U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov tried to free a two-year diplomatic logjam on Tuesday by saying they would seek to organize a conference, ideally this month.
The Russian official said there was broad agreement that the situation in Syria was dire. "Beyond that there are very many differences: who can take part in this format, who is legitimate and who is not legitimate," Itar-Tass quoted him as saying, on condition of anonymity.
Russia has been President Bashar Assad's main protector and weapons supplier and says that, although it is not wedded to him, it will not allow his departure to be a precondition of talks, as demanded by Western and many Gulf powers.
Kerry appears to have shifted the U.S. position by saying Assad's exit should be the outcome of negotiations on a transitional government, rather than the starting point.
But the Syrian opposition remains divided, not least between those who will and will not consider talking to Assad.
Samir Nashar, a representative of the umbrella Syrian National Coalition, which says Assad's departure must be guaranteed in any talks, said Russia wanted "groups other than the National Coalition to be present, such as the National Coordinating Body."
Most leaders of the rebellion dismiss the NCB because it opposes the armed uprising and also talks to the government.
Nashar said the National Coalition, whose leaders operate outside Syria, had decided it could not accept an invitation to the conference unless Assad's removal was guaranteed.
"We feel that we cannot discuss a political solution with a man who is responsible for killing thousands of people and destroying thousands of homes," he said. "The United States is trying to convince us that the result of these talks would be Assad's removal, but we remain unconvinced."
Russia has long argued that rebel intransigence — encouraged by Western and Gulf Arab insistence that Assad must go — is the main obstacle to a peace process.
"It is impossible to do this without the opposition," the Russian official said. "But what opposition? That's the question. We believe there is no clear center with which it is possible to conduct negotiations so that the commitments would then be fulfilled."
Nashar said the United States was considering trying to circumvent the official leadership of the National Coalition by enlisting figures such as Moaz Alkhatib for the conference.
The Sunni Muslim cleric resigned as head of the Coalition after other leaders, particularly those linked to the Muslim Brotherhood, opposed his proposal of talks with Damascus in exchange for the release of political prisoners.
But his resignation has not yet been accepted, and he remains one of the few leaders of the uprising who enjoys real popularity on the ground and, perhaps more importantly, the respect of pro-Assad Syrians, who regard him as a potential negotiating partner.
Separately, RIA-Novosti cited a diplomatic source as saying that Israeli Prime Minister Benjamin Netanyahu, already invited to Russia by President Vladimir Putin, wanted to visit him in Sochi this week.
RIA also cited a source in Jerusalem as saying the possible delivery of Russian S-300 air defense systems to Syria would be the main topic on the agenda. An Israeli official said only that Netanyahu and Putin were likely to meet sometime soon.
The Wall Street Journal reported on Wednesday, citing U.S. officials, that Israel had told Washington that Syria had begun payments for a $900 million upgrade of its Russian-made air defenses to the S-300 system, and an initial delivery was due within three months.
The system is designed to shoot down planes and missiles at up to 200 kilometers, and its use would complicate any outside military intervention in Syria's civil war.
Russia has expressed concern about Israeli air strikes in Syria this year, which Israeli sources say were aimed solely at preventing advanced weaponry getting to the Shiite Muslim militant group Hezbollah, a major Assad ally, in Lebanon.
The Kremlin official declined to specify to reporters whether Russia would be supplying the more advanced system.
"We are fulfilling contracts signed earlier," he said. "All weapons delivered under old contracts are purely defensive."