The Syrian army has retaken control of a road that was the only route into the government-held side of the second city of Aleppo, state media report.
Soldiers had driven back Islamic State (IS) militants, who seized the road from Aleppo to the towns of Khanaser and Ithriya last month, state TV said.
The UK-based Syrian Observatory for Human Rights confirmed the report.
Aleppo has been divided in two since 2012, with the government controlling the western half and rebels the east.
IS meanwhile controls a large swathe of territory to the east and north-east of the city, once Syria’s commercial and industrial hub.
Aleppo and its surrounding province have seen heavy fighting since the army – backed by Russian air strikes, fighters from Lebanon’s Hezbollah movement and Iranian militiamen – launched an offensive on rebel-held areas last month.
IS subsequently launched its own assaults on government positions around the town of Safira, in the countryside south-east of Aleppo. There was also fighting to the south, around Khanaser and Ithriya.
On 23 October, the jihadist group inflicted a blow on the government by capturing a checkpoint on the road between Ithriya and Khanaser.
That severed the army’s only supply route into the western half of Aleppo and reportedly caused sharp rises in the prices of basic goods.
But on Wednesday, state television reported that army units had regained control of the road “after eliminating a number of Daesh [IS] terrorists” and that it would reopen on Thursday.
Russian artillery ‘deployed’
In a separate development, the US defence department said rebels from the new, US-backed Syrian Arab Coalition had captured 200 sq km (77 sq miles) of territory from IS in north-eastern Syria.
Col Steve Warren, the spokesman for the US-led international coalition against IS, told reporters that 80 IS militants had been killed in the battle in the al-Hawl area, which involved around 1,000 SAC fighters taking on several hundred militants.
The SAC fighters were armed with ammunition supplied by the US at the beginning of October, Col Warren said, adding that they “showed us something here, and we are pleased by that”.
Meanwhile, a senior US diplomat said that 85 to 90% of Russian air strikes in Syria since the end of September had hit the moderate Syrian opposition and killed civilians in the process, despite Moscow “cynically” claiming that they were focused on “terrorists”.
Assistant Secretary of State for Near Eastern Affairs Anne Patterson told a Congressional hearing that Russia’s “primary intent was to preserve the regime” of President Bashar al-Assad, and not to combat IS and other jihadist groups.
Testifying alongside her, Assistant Secretary of State for European and Eurasian Affairs Victoria Nuland said Russia had also begun “fielding its own artillery and other ground assets around Hama and Homs”, two cities in western Syria.
Earlier, the Syrian Observatory for Human Rights reported that the civilian death toll from reported Russian air strikes on the IS-held town of Qaryatain on Monday had risen to 23.