Syria's military vowed on Sunday to keep up its campaign to regain control of the whole country, days after capturing large chunks of territory from the last rebel holdout in northwestern Syria.
Russia has heavily backed the Syrian government's offensive. The fighting led to the collapse of a fragile cease-fire that was negotiated with Turkey in 2018.
The advance of forces supporting Syrian President Bashar Assad into rebel-held areas of Idlib and Aleppo province has also sparked a largescale humanitarian crisis.
Nearly 600,000 people have fled the fighting since December. Most of the displaced are living in open-air shelters and temporary homes in freezing winter conditions closer to the Turkish border. Half of the displaced are believed to be children.
A main backer of the armed Syrian opposition, Turkey has sent in large military reinforcements into the rebel-held areas. But the buildup has not stopped the Syrian government advance.
Syrian military spokesman Gen. Ali Mayhoub said that government forces had gained a strategic advantage in recent days, according to a statement carried by Syria's state news agency. He said that Syrian troops advancing from around Aleppo's southern countryside had linked up with those coming from eastern Idlib.
The Syrian army had seized a geographical area of more than 600 square kilometers (230 square miles) and captured dozens of towns and villages, he added.
But the government campaign appears to be aimed at securing a strategic highway in rebel-controlled territory for now, rather than seizing the entire province and its the densely populated capital, Idlib.
The Britain-based Syrian Observatory for Human Rights said government troops were only a few kilometers from seizing full control of the strategic highway, know as M5. The highway links the national capital of Damascus with the country's north, which has for years been divided between government and opposition forces.
Turkey sent hundreds of military vehicles and troops into Idlib province in the past week. The buildup and the continued government advances sparked a rare clash on Feb. 3 between Turkish and Syrian soldiers that killed eight Turkish military personnel and 13 Syrian troops.
On Sunday, Mayhoub said the efforts to back the armed opposition "will not succeed in preventing the fast collapse'' of the rebel groups. Damascus considers all armed opposition as "terrorist organizations."
Rebels, including some of the most radical militant groups, control much of Idlib province and parts of the neighboring Aleppo region. These areas are home to some 3 million people - many of them displaced from other parts of Syria.
On Friday, Turkey's Defense Ministry warned its army would respond "even more forcefully'' to any attack on Turkish observation posts in northern Syria, adding: "Our observation posts will continue carrying out duties.''