Russia has warned that a "tragedy" was looming as the Syrian Army launched a counteroffensive in Syria's second city of Aleppo.
Syrian opposition activists say troops backed by fighter jets and helicopter gunships have began a major assault in Aleppo.
Russian Foreign Minister Sergei Lavrov told journalists on July 28 it was unrealistic to expect the government would stand by when armed rebels were occupying major cities.
"Pressure must be applied on all parties. We [Russia] have been saying this for many months in a row. Unfortunately, our Western partners prefer following a different course," Lavrov said.
"Essentially, along with several Syrian neighbor states they encourage, support, and direct an armed struggle against the regime, the price of all of this being even more bloodshed."
Russia has vetoed three UN Security Council draft resolutions intended to increase pressure on Syria's government to end the 16 months of violence. Moscow says Western and Arab nations should exert more influence on rebels to stop fighting.
In fighting on July 28 in Aleppo, government troops moved on the southern and eastern districts of the commercial hub. Those are the areas where rebel fighters have most concentrated their forces since they seized much of the city on July 20.
Opposition activists said fierce clashes were taking place in the neighborhood of Salaheddine. They said at least 10 soldiers and three rebel fighters were killed.
International concern has been mounting over what activists have said could be a looming massacre. Syrian troops have bombarded the city for the past week, unleashing artillery, and strafing it with aircraft. Government reinforcements have been pouring into the area in recent days.
Speaking in London on July 27, Turkish Prime Minister Recep Tayyip Erdogan said it was not possible "to remain a spectator" to events in Aleppo.
Meanwhile, opposition activists say some 160 people were killed on July 27 across Syria, including 17 in Aleppo.
The violence has also prompted an exodus of people, with the United Nations putting the number of Syrians in neighbouring countries at some 120,000.
In Saudi Arabia, a five-day fundraising campaign brought in $72.3 million for Syrian refugees, Interior Minister Prince Ahmed bin Abdul Aziz said on July 28.
Donors also provided medical equipment, clothing, tents, and blankets to be sent to Syrians who have fled to Lebanon, Iraq, Turkey, and Jordan.