Syria's opposition on Monday urged Russia, a key ally of President Bashar al-Assad, to put pressure on Damascus to help kickstart sputtering peace talks in Geneva.

The High Negotiations Committee (HNC), the main opposition group at the UN-sponsored talks, said it expects to meet a Russian delegation Tuesday in the Swiss city.

"We sincerely hope to persuade Russia to stand by the Syrian people," said HNC delegation chief Nasr al-Hariri after his latest talks with UN Syria envoy Staffan de Mistura.

"We hope that Russia will bet on the Syrian people and will not bet on one person who has decided to destroy the whole of Syria so as to remain in power," he added, referring to Assad.

Russia is a key ally of the Assad regime along with Iran, while the opposition, which is divided, has backing notably from Turkey.

The Geneva talks, the fourth under UN auspices and the first since last April, are struggling to get off the ground, and were not helped by suicide attacks in Syria's third city Homs which killed dozens at the weekend.

De Mistura managed to persuade regime and opposition negotiators to sit in the same room for a symbolic opening ceremony last week, but since then he has held separate talks with the different delegations, as during previous rounds.

Moscow and Ankara are co-sponsors of a fragile ceasefire, brokered at the end of December.

In Moscow, a foreign ministry source confirmed that deputy Russian foreign minister Gennady Gatilov would meet opposition negotiators along with all sides in Geneva.

Gatilov and Sergei Vershinin, head of the ministry's Middle East section, are both in Geneva for the 34th session of the Human Rights Council, currently under way.

"In the framework of the intra-Syrian talks in Geneva we have meetings with all parties, including the opposition which is represented by more than one group," said a ministry source.

"There is only one objective: to make progress towards a political resolution in the spirit of (UN Security Council) Resolution 2254 .. and to gain as much as possible from the ceasefire," the source told AFP.

In Geneva, al-Hariri sounded more upbeat after his latest meeting with the UN envoy.

"This meeting was more positive than the one before," he told reporters.

He added that he believed Moscow was showing signs of openness.

"It has tried to be neutral ... we see an openness in their position, especially vis-a-vis the revolutionary moderate factions," he said, referring to moderate rebels.

"The fact that it has recognised these factions as a negotiating party is an indication of Russia's openness and we are hopeful that tomorrow's meeting is also a positive indication."

He added: "We hope that these theories will be put in practice and we will see support for the peace process which would ultimately lead to peace by putting pressure on the (Damascus) regime."

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