The SDF had been holding the town in recent days amid intense fighting with the Syrian National Army (SNA) and other Turkey-backed groups.
Biden said US forces on Sunday conducted a dozen precision strikes within Syria targeting camps and operatives of the terrorist group Islamic State.
Earlier, the military noted that it had decided to reinforce troops for defense purposes throughout the Golan Heights region bordering Syria.
Syria's army command notified officers that Assad's 24-year rule had ended following a lightning rebel offensive.
Hezbollah leaving Assad’s territory has made his regime vulnerable, enabling significant gains by Syrian opposition, though experts agree that Israel doesn’t have a side to support
The US noted that President Bashar al-Assad's "regime" has been part of an ongoing refusal to "engage in a political process," which has "created the conditions now unfolding."
Early reports showed rebels walking around the seemingly abandoned but ostentatious palace.
Russian and Syrian warplanes bombed the area near the border with Turkey on Thursday to try to push back an insurgent offensive that has captured territory for the first time in years.
The incident marks the largest tribesman attack on Syrian Democratic Forces (SDF) sites since the start of the Arab tribal rebellion in 2023.
"The moment I heard that my kids were dead, I was holding a six-month-old baby that had just been killed in Adawiya. So, I was imagining what had happened to my kids," said a former Syrian rebel.