Biden administration officials view the potential collapse of Bashar al-Assad's regime within days, according to a report published Saturday.
Citing five American officials, CNN reported that there is not yet a formal evaluation of Assad's future, and his collapse is not guaranteed.
One senior US official told the network that "the emerging consensus is that is an increasingly plausible scenario".
Another official said: "Probably by next weekend the Assad regime will have lost any semblance of power".
"Only thing that would delay a rebel conquest would be a well-organized coup and reorganization, but Assad's folks have done a good job of stifling any potential competitors," the official added, according to the CNN.
Another source said the anti-regime groups' progress has been largely due to regime forces avoiding engagement in the conflict.
"The question is whether regime forces actually stand their ground when it comes to Damascus," they said.
Meanwhile, Bashar al-Assad is making moves to cling to power, including indirect diplomatic overtures to the US and President-elect Donald Trump, Bloomberg reported, citing sources with direct knowledge of the situation.
Assad is signaling a willingness to negotiate a deal to retain control over the remaining territory held by his forces or secure safe passage into exile if necessary, Bloomberg reported.
According to sources, one proposal Assad relayed to the Washington through the United Arab Emirates involved severing Syria's ties with Iran-backed militant groups, including Hezbollah, in exchange for Western powers leveraging their influence to halt the fighting.
In a separate effort, Assad reportedly sent a senior Christian leader to meet Hungarian Prime Minister Viktor Orban, citing an alleged threat to Syria's Christian minority, asking the premier to relay these concerns to the incoming US administration.
Renewed fighting between regime forces and anti-regime groups broke out on Nov. 27 in rural areas west of Aleppo.
By Nov. 30, opposition forces had taken control of most of Aleppo's city center and established dominance across the Idlib province.
Following intense clashes on Thursday, groups took control of the Hama city center from regime forces.
Anti-regime groups also seized several settlements in the strategically important Homs province, which leads to Damascus, and began to advance.
On Friday, Syrian opposition groups took control of Daraa in southern Syria, near the Jordanian border.
Earlier on Saturday, they seized total control of the Suwayda province in southern Syria. On the same day, local opposition forces in Quneitra gained control of the provincial capital.
On Dec. 1, the opposition Syrian National Army launched Operation Dawn of Freedom against the terrorist group PKK/YPG in the Tel Rifaat district of Aleppo's countryside, liberating the area from terror elements.
