The Syrian army retook a strategic town from the militant Islamic State (IS) group on Thursday, paving the way for the reopening of its sole supply route to main northern city Aleppo.
The Syrian Observatory for Human Rights said troops still needed to clear the militants from hills overlooking the key highway before it could be fully secured.
The road through the town of Khanasser is the sole link between government-held areas in and around Aleppo and those in the rest of the country.
State news agency SANA hailed its recapture just two days after its fall to the militants.
The army’s counteroffensive was backed by Russian air strikes which killed numerous IS fighters.
It is not the first time that the government’s supply route to Aleppo has been cut. Militants severed it in 2013 and IS also did so last year before being pushed back.
The new fighting for the road comes with the army on the offensive north and west of Aleppo, where militant forces in the east of the city are almost completely surrounded.
That offensive is supposed to come to an end when a Russian and US-brokered ceasefire goes into effect at 2200 GMT on Friday.