Russia and Iran have agreed to closer military co-operation, in a move announced during a visit to Moscow by President Masoud Pezeshkian.
The two countries signed a 20-year “strategic partnership” treaty, covering areas ranging from defence and technology to energy and trade.
Iran already supplies drones to Russia, as well as, according to Western intelligence, ballistic missiles.
Russia has cultivated closer ties with Iran, along with China and North Korea, since its full-scale invasion of Ukraine began in February 2022.