But U.S. Defense Secretary Leon Panetta, speaking aboard a military aircraft Sunday traveling to North Africa and eventually the Middle East, predicted that government forces' violent crackdown in Aleppo will prove "a nail in Assad's coffin" by turning even more people against President Bashar al-Assad and his government.
Aleppo was just one area hit by violence on Sunday. The city saw 11 deaths out of 114 nationwide, according to the opposition Local Coordination Committees of Syria.
At least 41 people were killed in Damascus and its suburbs, a figure that includes 18 unidentified bodies found charred on farms in Moadamiyeh, where a total of 36 people were reported dead. Another 33 died in the province of Daraa, and nine apiece were slain in the provinces of Homs and Deir Ezzor, the group said.
State media and activists reported violence elsewhere as well, including clashes in suburbs near the southwestern city of Daraa and the northwestern city of Idlib.
That said, Aleppo has gotten much of the attention in part because controlling it is considered key for the embattled regime and the anti-government fighters.
Regime forces are preventing fuel and food from entering Aleppo neighborhoods controlled by rebel fighters, opposition activists said. Rebels have had to set up medical clinics in homes.
"The situation in the city of Aleppo is very critical and quite serious," said activist Abo Hamdi from the neighborhood of Salahuddin, adding the "Free Syrian Army is preparing for a fierce battle."
Syrian TV reported that "terrorists" suffered heavy losses after clashes in three neighborhoods.
With relentless attacks rocking Aleppo, the head of a prominent Syrian opposition group pleaded for world allies to help arm rebels.
"Our friends and allies will bear responsibility for the terrifying massacres that will happen in Aleppo if they don't move soon. This regime is planning for a big massacre in Aleppo," Abdulbaset Sieda, head of the Syrian National Council, told reporters in Abu Dhabi.