Details added (the first version was published at 23:03)
The Syrian government has agreed to participate in a peace conference initiated by the United States and Russia, the Russian Foreign Ministry said Friday, dpa reported.
"We received confirmation from Damascus that the Syrian government is in principle ready to take part," spokesman Alexander Lukashevich was quoted as saying by the Interfax news agency.
However, the governmet of President Bashar al-Assad had not publicly confirmed its participation by late Friday.
Washington and Moscow have put forward a plan to bring both Damascus and the opposition to the negotiating table in a bid to end the country's 26-month conflict, which the United Nations estimates has killed at least 80,000 people.
Lukashevich said that while a number of Syrian opposition groups had confirmed their participation, their lack of unity represented a major obstacle.
A date for the conference has not yet been set.
Russia, which is Syria's key ally and main arms supplier, also wants Saudi Arabia and Iran to attend the conference.
Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry spoke on Friday and are to hold further talks on the issue on Monday in Paris.
"They will discuss the Syrian crisis and prospects of an international conference on Syria," a foreign ministry source was quoted by the Itar-Tass agency as saying.
The Syrian National Coalition opposition group was expected to decide on its participation in the proposed parley at a meeting in Istanbul.
Coalition member Samir al-Nashar expressed skepticism about the regime's participation, saying: "We want to hear the acceptance officially from the Syrian government itself."
The opposition has repeatedly demanded that al-Assad step down for any political solution to be achieved.
Meanwhile, the coalition accused al-Assad's troops of using chemical gases in an attack on the Damascus suburb of Adra that killed four people late Thursday. It said 50 people had suffered from suffocation and allergic reactions.
"The coalition condemns the international failure facing al-Assad's use of chemical weapons ... and rejects any projects aimed at transforming the Syrian situation into a permanent crisis," the group said.
The United States, Britain and Israel have said there is evidence that chemical weapons have been used in Syria, but the US wants to see conclusive proof that such weapons have been deployed before considering any action.
With Damascus and the rebels having accused each other of using chemical weapons, the United Nations has repeatedly called on Damascus to allow UN inspectors to enter the country.
In Syria, rebels launched a counterattack on troops in the strategic town of al-Kussair near the border with Lebanon, activists said.
Al-Kussair lies near a major highway connecting Damascus with the government-controlled cities of Tartous and Latakia.
The rebels allegedly use the area to smuggle weapons from Lebanon.
Al-Assad's troops, backed by fighters with the Lebanese Shiite militia Hezbollah, have battled in the past few days to regain control of the town.