Syrian troops began clearing barricades from the main highway between Damascus and Aleppo on Saturday after recovering full control of the road in a Russian-backed offensive, Syrian state media reported.
It marks a major gain for President Bashar al-Assad, as reopening the M5 highway will restore the shortest route between Syria's two biggest cities for the first time in more than seven years of conflict.
A reporter with state-run al-Ikhbariya news channel, broadcasting from the highway on the Aleppo outskirts, said clearing the barriers started in the early hours of Saturday.
Restoring government control over the M5 has been seen as a major objective of a Russian-backed offensive that has been underway since early December in the rebel-held northwest.
The offensive has forced more than 800,000 people to flee.
The Syrian Observatory for Human Rights, which reports on the war using a network of sources on the ground, said government forces had captured a belt of territory around the road, securing it completely.
Observatory Director Rami Abdulrahman told Reuters the Russian-backed offensive may stop now that the road had been secured but added that the government could yet seek to seize more ground north of Aleppo to secure the city.
The reopening of the highway was part of a 2018 agreement between Russia and Turkey which was concluded with the stated aim of stabilising the situation in the Idlib region of the northwest, a major foothold for the anti-Assad insurgency.
The pact called for establishing a de-militarised zone between the warring sides in addition to the reopening of a second highway, the main road linking Aleppo with the government-held coastal region.
In agreement with Russia, Turkish forces deployed into the northwest at a dozen observation posts.
But tensions have spiralled between Russia and Turkey during the latest offensive, as 13 Turkish soldiers have been killed by Syrian attacks in the past two weeks.
Turkey has vowed to drive back Syrian troops beyond the Turkish observation posts in Idlib by the end of this month.
Turkish Vice President Fuat Oktay said on Saturday Turkey has fulfilled its responsibilities in the Idlib region in line with its de-escalation agreements with Russia and Iran, which also backs Assad.