Top Russian security official Sergei Shoigu held talks with his Iranian counterpart in Tehran on Tuesday, Russian and Iranian media said, days after meeting North Korean leader Kim Jong Unin Pyongyang.
Russia has deepened ties with Iran and North Korea, both of which are hostile to the United States, since the start of its war in Ukraine.
The United States views the growing relationships with concern and says both countries are supplying Russia with ballistic missiles for use in the conflict, something Moscow denies.
Shoigu's trips are taking place at a crucial moment in the two-and-a-half-year war, as Kyiv presses the United States and its allies to let it use Western-supplied long-range weapons to strike targets such as airfields deep inside Russian territory.
President Vladimir Putin said last week that Western countries would be fighting Russia directly if they gave the green light, and that Moscow would respond.
The Nour news agency, affiliated to Iran's Supreme National Security Council, said Shoigu met his Iranian opposite number, Ali Akbar Ahmadian. There was no immediate information on the outcome of the meeting.
Russia has repeatedly said it is close to signing a major agreement with Iran to seal a strategic partnership between the two countries.
Shoigu was Russian defence minister until May, when he was appointed secretary of the Security Council that brings together President Vladimir Putin's military and intelligence chiefs and other senior officials.
Apart from meeting North Korea's Kim last week, he also held talks in St Petersburg with Chinese Foreign Minister Wang Yi.
Reporting by Moscow and Dubai newsrooms