The fight for Al-Bab has seen the bloodiest clashes of Ankara's half-year meddling in the conflict-torn country and its capture would be one of the most significant reverses for Daesh (ISIL) in Syria.
Speaking to NTV television, Turkish Defense Minister Fikri Isik said half of the town of Al-Bab was in the hands of Turkish troops and allied pro-Ankara Syrian rebels, after the government repeatedly said it was "largely under control".
"We estimate there are less than 100" Daesh fighters left in Al-Bab, Isik told NTV. "But they are very dangerous people. Some are snipers, some are potential suicide bombers."
He said the operation to surround Al-Bab was "over" with troops now moving from district-to-district to "clean up" the town, AFP reported.
Last week, the Syrian Foreign Ministry sent two letters to the UN secretary-general and the UN Security Council president calling on them to make Turkey stop its violations against Syria.
Syria has condemned Turkey’s "repeated crimes and attacks against the Syrian people and violations of the sanctity and unity of Syria’s territory," and demanded that the Security Council "put an end to the violations which the Turkish regime is committing against the Syrian people."
Al-Bab is one of Daesh’s last remaining strongholds near the Turkish border. Capturing the city is of strategic importance to Turkey in order to prevent the Syrian Kurds taking it and unifying their own territories.