The Turkish military's victory in Afrin coincided with the anniversary of a more decisive battle victory for Turks, the battle of the Dardanelles in World War I, which ended with victory of the Ottoman army against the Allied forces in 1915.

Erdogan was speaking in Canakkale, the Turkish province that hosts the famous Dardanelles Strait.

According to Turkish sources, more than 100,000 civilians fled the city in the last few days, as Turkish planes dropped leaflets in Kurdish and Arabic over the city calling on the population to evacuate ahead of an ultimate offensive.

Considered by Ankara as a terrorist group, the YPG was trained and equipped by the United States to fight against the Islamic State (IS), which sparked a meltdown of relations between the two NATO allies.

According to figures released by the Turkish army, more than 3,500 "terrorists have been neutralized" during the operation, which means they were either captured, wounded or killed.

The official casualty figure for Turkish soldiers in the operation stands at 271, with 46 killed, and 225 others injured.

Erdogan has signalled he could broaden the offensive into northeastern Syria, ultimately targeting PKK bases in Iraq to quash Kurdish aspirations for self-rule.

Turkish commandos have been fighting PKK militants in northern Iraq since last week, according to state-run media.

Analysts said if the capture of Afrin city is the main target of the Turkish incursion, there are more risks ahead for the military.

"It's still a risky and tricky business there. There would be resistance pockets in the city and there are undoubtedly many improvised explosive devices and booby traps lying around," said security expert Abdullah Agar on NTV news channel.

He said a street-by-street operation was underway with Turkish special forces sent there in the last weeks of the offensive.

A Turkish victory in Afrin could push the U.S. to ensure that Kurdish fighters withdraw from the town of Manbij to the east of the Euphrates River, Agar noted.

US special troops are deployed in the Kurdish-held town and the dreaded possibility of a military clash there between two NATO troops has pushed Ankara and Washington toward a reconciliation.