Syria's army on Sunday announced it had captured the vital Abu Duhur military airport in the country's northwest, more than two years after losing it to rebels and jihadists.

"After a string of special operations, units from our armed forces in coordination with allied fighters succeeded in their military operation and took control of the Abu Duhur military airport in Idlib province," the army said in a statement.

"Engineering units are now dismantling and clearing mines, explosives, and bombs planted by terrorists in the area," he said.

An alliance of jihadists and rebels overran the vast majority of Idlib province in 2015, seizing Abu Duhur in September of that year.

Syrian troops had been advancing on the northwest province of Idlib, and Abu Duhur in particular, as part of a fierce offensive launched in late December with Russian backing.

Regime loyalists have seized dozens of towns and villages as part of the assault, but the air base's capture marks the first military installation Syrian troops have managed to retake in Idlib.

Moscow on Sunday confirmed that allied troops were now in control of Abu Duhur.

With its capture, the Syrian army said, troops could now secure a key route leading from the neighbouring province of Aleppo south to the capital Damascus.

Syria's uprising erupted in 2011 with protests against the rule of President Bashar al-Assad, but a government crackdown paved the way for a full-blown civil war.

The government lost swathes of Syrian territory in the first few years of the conflict but, since Russia militarily intervened in 2015, it has steadily regained the upper hand.