UN Security Council to discuss Syria after Assad's ouster

“The United States strongly supports a peaceful transition of power to an accountable Syrian government through an inclusive Syrian-led process,” Blinken said. “During this transitional period, the Syrian people have every right to demand the preservation of state institutions, the resumption of key services, and the protection of vulnerable communities.”

Blinken said the United States will support international efforts to hold Assad and others accountable for abuses against the Syrian people and detention of civilians such as U.S. journalist Austin Tice.

Assad was accused of war crimes and crimes against humanity during the country’s civil war, including a 2013 chemical weapons attack on the outskirts of Damascus.

More than half a million Syrians died in the war, and the conflict displaced at least half the country’s pre-war population of 22 million people.

Assad’s fall prompted crowds to gather and celebrate in Damascus and elsewhere.

Rebels opened prisons where the Assad government held thousands of people as part of its crackdown against the uprising that began in 2011 against his rule.

There was continued focus Monday on the Saydnaya prison outside of Damascus, where the White Helmets rescue organization said it deployed teams to search for potential hidden, underground cells where people may still be held.

Russian news agencies said Sunday that Assad and his family arrived in Moscow and were granted asylum in Russia.

The downfall of Assad was stunningly quick, with the rebels capturing the cities of Aleppo, Hama and Homs in a matter of days as the Syrian army ended any opposition. The rebels are led by the Hayat Tahrir al-Sham group (HTS) which has its origins in al-Qaida and is considered a terrorist organization by the United States and the United Nations.

Abu Mohammed al-Golani leads HTS and could chart the country's immediate direction. He is a former al-Qaida commander who cut ties with the group years ago and says he embraces pluralism and religious tolerance.

But there are bitter divides in the country. Turkey-backed opposition fighters are battling U.S.-allied Kurdish forces in the north, and the Islamic State group is still active in some remote areas.