Live updates: Follow the latest on the Syrian rebel advance
President Joe Biden on Sunday said the collapse of the Assad regime was a “fundamental act of justice” and that the US will work with all in the country, including the US-designated terrorist group Hayat Tahrir Al Sham, as Syria's next chapter is written.
In his first comments since rebels seized Damascus and president Bashar Al Assad fled to Moscow, Mr Biden described a moment of “considerable risk and uncertainty” for Syria. “But I also believe it’s the best opportunity in generations for Syrians to forge their own future,” he said from the White House.
The US has about 900 troops in Syria, most of them in the north-east, where they have been based for nearly a decade to help Kurdish forces fight ISIS. Mr Biden said he is “clear-eyed” that ISIS will try to take advantage of any vacuum to re-establish itself or create a safe haven.
“We will not let that happen,” he said, noting that US forces on Sunday had conducted dozens of air strikes in Syria on ISIS camps and operatives. The operation struck more than 75 targets using US Air Force planes including B-52s, F-15s and A-10s, US Central Command said.
The US “will support Syria's neighbours, including Jordan, Lebanon, Iraq and Israel, should any threat arise from Syria during this period of transition,” Mr Biden said. He said he will speak to regional leaders in the coming days.
A senior US administration official on Sunday said Washington is in contact with all Syrian groups, including Hayat Tahrir, which the UN has also designated as a terrorist group.
“It’s safe to say there’s contact with all Syrian groups as we work to do whatever we can to support the Syrians through the transition,” the official told reporters.
Hayat Tahrir leaders are "saying the right things so far, doing the right thing … we will intend to engage with them appropriately and with US interests in mind," the official added.
The group's leader, Abu Mohammed Al Jawlani – who has dropped his nom de guerre for his original name, Ahmad Al Shara – has sought to project a moderate stance and distance himself from his extremist past that includes fighting for an Al Qaeda affiliate.
The Biden administration, which ends with president-elect Donald Trump's inauguration on January 20, had until now maintained a cautious stance on its Syria messaging as Hayat Tahrir swept across Syria.
Mr Biden said the US would engage with "all Syrian groups … to establish a transition away from the Assad regime toward an independent … and sovereign Syria with a new constitution, and a new government that serves all Syrians".
ISIS threat
He said Mr Al Assad's fall from power was a direct result of Israel's attacks on Hezbollah and Iranian interests, and Ukraine's fight against Russia, both of which have been pressed with the “unflagging support of the United States”.
Mr Trump at the weekend gave early indications about his Syria policy, reflecting his “America First” stance.
He said on Truth Social on Saturday that the US should stay out of Syria’s conflict, and should have “nothing to do with” what comes next. He tried to withdraw US troops from Syria during his first term but military officials convinced him to let them stay, as they were crucial in preventing a resurgence of ISIS.
Frank McKenzie, a retired general and the former head of Centcom, said Mr Trump would have to take a "good, hard look" at his Syria policy when he takes office.
"Our interest in Syria is probably preventing violent extremist groups from being able to plan and execute attacks against our homeland and the homeland of our friends and partners abroad," Mr McKenzie told ABC.
Colin Clarke, a Syria expert and senior research fellow at The Soufan Centre, warned of the risks Syria faces as external and internal interests vie for influence.
Mr Al Shara is saying the "right thing" by promising not to allow Syria to be turned into a launch pad for terrorist groups.
But "are they going to be able to exercise a monopoly on the use of force over the entire country? I doubt it," Mr Clarke told The National. "There's other groups operating on Syrian soil. I would just urge caution that we're not really out of the woods here."
He said that Mr Biden's influence in the region is perceived as weak, so all eyes are on Mr Trump's administration, particularly in terms of negotiations with Turkey. Ankara wants the US out of north-east Syria and to stop backing the Kurds there.
Congressman French Hill, the Republican co-chair of the Syria Caucus, said: “Since the start of the war, we have only heard the demands of 'Assad or we burn the country'. Today, the country finally may have stopped burning.”
Mr Hill said that moving forward, Washington will “need to work with our regional partners to pursue the merits of UN Security Council Resolution 2254," which calls for a free and democratic Syria.
Gerry Connelly, a senior Democratic congressman, warned on Sunday that “revolutions often end with disappointment and suppression".
“There is a window to build a democratic Syria. But it is fragile,” he added.
Mouaz Moustafa, the executive director of the Washington-based Syrian Emergency Task Force who has lobbied forcefully for Syrian democracy, told The National he “doesn’t have the words to describe how he feels".
“The Syrians have their country back and the Syrians can finally build a democracy. True hope now is blooming in Syria.”
Mike McCaul, Republican chairman of the House foreign affairs committee, said: "There must be accountability for the egregious crimes committed by the Assad regime, Russia, Iran and Hezbollah against the Syrian people."
Austin Tice
Mr Biden also said the US believes journalist Austin Tice, who has been missing since his 2012 abduction in Syria, is thought to still be alive.
“We believe he is alive. We think we can get him back, but we have no direct arrangements to that yet,” he said. Earlier, Tice’s mother expressed optimism her son would be coming home, telling journalists he would need lots of “care and attention” when he is freed.
The US is offering a reward of up to $1 million for information leading directly to Tice's safe location and return.
At the UN, Secretary General Antonio Guterres called for international support to ensure that any political transition in Syria is “inclusive and comprehensive”.
"After 14 years of brutal war and the fall of the dictatorial regime, today the people of Syria can seize an historic opportunity to build a stable and peaceful future,” Mr Guterres said in a statement. “Syria’s sovereignty, unity, independence and territorial integrity must be restored.
Ellie Sennett and Adla Massoud contributed to this report from Washington and New York
