Chief of General Staff Gen. Hulusi Akar and Gen. Valery Gerasimov held a closed-door meeting following a ceremony at the General Staff Headquarters in Ankara, the source said on condition of anonymity due to restrictions on talking to the media.
Akar and Gerasimov are to discuss Syria and military cooperation, a Russian defense ministry spokesman said earlier.
Although Russia is one of the main backers of Syrian regime leader Bashar al-Assad while NATO member Turkey backs opposition forces such as the Free Syrian Army (FSA), both sides are targeting Daesh terror group in Syria.
Operation Euphrates Shield to remove Daesh from the northern border region has seen Turkey back FSA forces on the ground with special forces, tanks, artillery and airpower.
A U.S.-Russia-brokered cease-fire that began Monday evening is largely holding across Syria and has been extended for a further 48 hours.
Relations between Ankara and Moscow have been repaired since Turkey shot down a Russian warplane over the Syrian border in November last year for violating Turkish airspace, with President Recep Tayyip Erdogan meeting President Vladimir Putin on Aug. 9 in St. Petersburg and Russia lifting sanctions against Turkey and restoring economic ties.