The new international envoy for Syria says change is both "urgent" and "necessary" and that it must meet the needs of the Syrian people.
Lakhdar Brahimi was speaking in New York on September 1, his first day on the job as the Syrian envoy for the United Nations and Arab League.
Speaking to the broadcaster Al Arabiya, Brahimi said the onus was on the government rather than the rebels to halt the violence, which has left at least 20,000 dead since the uprising against Syrian President Bashar al-Assad began last year.
Brahimi said he had no new ideas to end the conflict and has yet to decide when to make his first visit Damascus in his new role.
Brahimi's comments came as activists said rebels captured an air-defense facility in the east of the country near the border with Iraq.
Meanwhile, the battle for control of Aleppo intensified, with government aircraft and ground forces pounding it with bombs and mortar rounds as rebel fighters fought off troops in the narrow alleys of the city's old quarter.
In Moscow, Russian Foreign Minister Sergei Lavrov labeled as unrealistic demands that Assad step down as a precondition for settling the crisis.
"When our partners say that the [Syrian] government must stop first and must withdraw all its soldiers and weapons from cities -- and only then call on the opposition to do the same -- well, this is a completely unworkable scheme. Either people are naive or it is some sort of provocation," Lavrov told university students.
In Amman, the government of Jordan said it will "reconsider" its open-border policy if its international appeal for $429 million is not met.
Minister of International Cooperation Jaafar Hassan said the influx of refugees from Syria has reached as high as 4,000 persons per day.
He said the country's sole Syrian refugee camp has reached full capacity, and, to expand it, the Jordanian government needs $150 million.
With reporting by AFP and AP