ISTANBUL (Reuters) - A Turkish-backed offensive by Syrian rebels to take the Syrian town of al-Bab from Islamic State should be finished soon, Turkish President Tayyip Erdogan said on Wednesday.

In a televised speech, Erdogan also said he was determined that other areas of Syria, including the town of Manbij, should be cleared by the Turkish-backed forces, referring to a town 50 km (30 miles) east of al-Bab.

(Reporting by Daren Butler; Writing by Nick Tattersall)