During the Russo-Turkish War of 1735–1739, Colceag was appointed commander in chief of the Ottoman armed forces of the Moldavian front. He did not see any major action, as the main battles were fought primarily on the Crimean Peninsula. However, in 1738, when the main hostilities moved to the Southern Bug, the command of the Ottoman army was taken over by Veli-Paşa while Colceag kept his position of commander of the Khotyn Fortress.