Russia's prime minister has said Syrian President Bashar al-Assad made a "grave, perhaps fatal error" by delaying political reforms, as Damascus courted opposition forces.
"He should have acted much more quickly and reached out to the peaceful opposition which was ready to sit at the negotiating table with him," Russian news agencies quoted Dmitri Medvedev as saying Sunday.
"It's a grave error on his part, perhaps fatal," he said, in a rare criticism of Assad by Syria's traditional ally Moscow.
"It seems to me that his chances of staying (in power) are shrinking day by day," Medvedev told CNN television on the sidelines of the Davos World Economic Forum in Switzerland.
Syria's high judicial council, meanwhile, announced a suspension of prosecutions of opposition members so they can join a national dialogue, state media reported.
"The high judicial council has decided to discontinue all prosecutions against opposition forces and individuals so they may participate in the national dialogue," the official news agency SANA said, without elaborating.
On Saturday, Interior Minister Mohammed al-Shaar vowed to ease the return of opposition members living in exile to allow them to join a national dialogue proposed by Assad on January 6.
In a rare speech, Assad proposed a dialogue with opposition figures who were not "slaves of the West" on condition that "terrorist attacks" came to a halt.
The regime has consistently branded activists and insurgents alike as terrorists.
Shaar, in comments reported by state media, cautioned that the directive allowing Syrian opposition figures living abroad to return was not a blanket amnesty.
He emphasised that "there is a big difference between those who safeguard their nation and those who are complicit in foreign agendas."
Medvedev on Sunday reiterated Russia's stand that only the Syrian people can decide the fate of Assad, whose departure the West has long called for in the face of a 22-month uprising that has left over 60,000 dead according to the UN.
"I personally a few times called Assad and said, 'You need to start reforms, you need to sit at the negotiating table,'" he said, according to the CNN transcript.
"In my view, unfortunately, the Syrian authorities turned out not to be ready for this."
UN humanitarian aid chief Valerie Amos, meanwhile, held talks in Damascus with Foreign Minister Walid Muallem and other senior officials, her spokesman Khaled al-Masri told AFP.
The UN said on January 21 it would conduct a major humanitarian operation in Syria. The UN suspended operations in Syria in early December and withdrew non-essential foreign staff due to deteriorating security.
Social Affairs Minister Jassem Zakaria, who also met Amos, urged UN humanitarian agencies to respect their pledges towards families hit by the conflict, SANA reported.
Zakaria protested the "bad living conditions of Syrian families in camps (abroad) when Syria has been offering to help all those who take refuge (on its territory), without a single tent having to be erected."
Almost 600,000 Syrians out of an estimated two million displaced have fled to neighbouring countries, many of them living in tent camps. The UN says four million Syrians need emergency aid.
On the ground in Syria, violence raged on Sunday between rebels and loyalists, costing at least 67 lives, including 24 civilians, 19 rebels and 24 soldiers, the Syrian Observatory for Human Rights reported.
Fighting erupted in the Port Said area of south Damascus and spread to the nearby Qadam train terminal, while the army shelled nearby districts.
On the Damascus outskirts, warplanes pounded the Eastern Ghuta region, the watchdog said. An activist network reported shelling against the southwest suburb of Daraya from Mazzeh military airport.
Israeli media meanwhile, reported that the army there had on Sunday deployed two Iron Dome missile defence batteries to the north of the country for the first time, reflecting growing tension around the border with Syria.
Other reports said Israeli Prime Minister Benjamin Netanyahu last Wednesday held emergency talks with security chiefs and his inner cabinet on the risk of Syria losing control over its weapons of mass destruction.