Secretary of the Russian Security Council Nikolai Patrushev is in Tehran for consultations with Iranian officials.
"In Tehran, Patrushev will hold planned Russian-Iranian consultations on security issues with the participation of Security Council specialists and representatives of several ministries and departments of the two countries," the press office of the Russian Security Council said.
The visit comes amid allegations that Iran is supplying Russia with kamikaze drones.
Tehran admitted a few days ago that it had sent a "small number" of drones to Moscow, although it said this was before the start of the Russia-Ukraine war in late February.
Russia has been using Iranian drones to attack Ukraine's energy infrastructure in recent weeks