Russian and US jets practiced a close approach to a minimally safe distance of 5.5 kilometers, said Russian army officer Col. Gen. Andrei Kartapolov, according to the Sputnik news outlet.
"Today at 11 a.m. Moscow time, Russian and US air forces carried out joint drills on actions by crews and land personnel in cases when aircraft fly in close proximity to each other," Kartapolov was quoted by Sputnik as saying.
The announcement comes a month into Russian operations in Syria, aimed at bolstering embattled president Bashar Assad.
Moscow has butt heads with Washington and other Western capitals over its operations in Syria, amid accusations that it is striking non-jihadist rebel groups and not Islamic State and al-Qaeda fighters.
Officials in Russia and the US, which is also carrying out airstrikes in Syria aimed at weakening the jihadists, had previously said coordination between them was not in the cards.
There was no official US confirmation of the joint drills.