Rebels have staged a whirlwind advance over the past week, seizing Syria's second city, Aleppo, and much of the surrounding countryside, reaching within a few kilometers of Hama on Tuesday.
Russia, a key ally of Assad since 2015, has provided significant military support to his regime during the country’s prolonged civil war.
Aleppo and Idlib fall to opposition; regime and Iranian militias retreat amid intense battles and airstrikes.
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
Rebels and the Syrian Observatory for Human Rights war monitor said insurgents had captured villages, including Maar Shahur, a few miles north of the city.
Jamaa is a veteran Hezbollah operative who has held several positions with the Hezbollah terrorist organization throughout the years, particularly with a focus on Syria.
Two Iraqi security sources and a senior Syrian military source told Reuters on Monday that hundreds of Iraqi Shi'ite militia fighters had crossed the border late to help Assad's army fight rebels.
Iran wants the US to leave eastern Syria, where the US is fighting ISIS alongside the Syrian Democratic Forces, a mostly Kurdish force.
The attack was initiated by Hayat Tahrir al-Sham. Formerly known as the Nusra Front, it was al Qaeda's official wing in the Syrian war until breaking ties in 2016.
The weapons may include missiles, production and storage facilities of chemical weapons like sarin, tanks, and armored personnel carriers.