UN-Arab League envoy Lakhdar Brahimi Thursday called for the formation of a transition government in Syria until elections can be held, ahead of his visit to Moscow at the weekend.
"We need to form a government with all powers ... which assumes power during a period of transition," Brahimi said in Damascus. "That transition period will end with elections."
The opposition has repeatedly demanded that President Bashar al-Assad step down before any political solution can be reached.
Brahimi said the Syrian people "need, want and aspire to genuine change".
"It's even clearer now that the change, which is needed is not cosmetic or superficial."
Brahimi denied speculation that he was in Syria to promote a Russian-US plan to end the country's 22-month conflict, which the opposition says has claimed more than 45,000 lives.
"The situation in Syria poses a danger to the whole world," he said.
Brahimi arrived in Syria on Sunday and met with al-Assad.
The veteran Algerian diplomat has failed to make any progress towards brokering a deal since starting his mission in August.
Brahimi is to meet Russian Foreign Minister Sergei Lavrov in Moscow on Saturday, according to a Russian official.
"We plan to discuss the whole range of issues concerning political and diplomatic settlement in Syria, including Brahimi's recent efforts that are targeted at stopping violence and the launch of a
comprehensive national dialogue between the authorities and the opposition in compliance with the Geneva agreements," said Russian Foreign Ministry spokesman Alexander Lukashevich.
He was referring to agreements reached in Geneva in June at the Action Group for Syria meeting.
Calling for "a legally elected president" to step down was not a part of the Geneva agreements, Lukashevich said, according to Itar Tass news agency.
Lavrov Thursday met in Moscow with Syrian Deputy Foreign Minister Faisal al-Mokdad and renewed Russia's call for talks between Damascus and the opposition.
"There can be no substitute to a peaceful solution in Syria, which can be achieved through dialogue," he said, according to a Foreign Ministry statement.
Russia, a traditional ally and arms supplier of Syria, has repeatedly vetoed United Nations resolutions against al-Assad.
On the ground in Syria, at least 11 rebels were killed in clashes with government troops in the northern province of Idlib, reported the opposition Syrian Observatory for Human Rights.
At least 16 soldiers were killed and 20 injured in a car bombing and fighting with insurgents in Idlib, added the Britain-based organization.
The state Syrian news agency SANA said government troops had carried out "a series of qualitative operations and eliminated several terrorists", referring to opposition rebels, in suburban areas of Idlib.
It added that military experts had defused an explosive device weighing 40 kilograms in the same province.
Rebels, fighting to oust al-Assad, have recently claimed major gains in northern Syria.
News from Syria is difficult to verify as authorities have barred most foreign media from the country since the uprising against al-Assad's rule started in March last year.