Russia secretly aiding Iran in development of supersonic cruise missiles, reports say

Leaked documents reveal that Russia has secretly assisted Iran since 2023 under a program codenamed C430L to develop supersonic cruise missiles. Arranged by Rosoboronexport and NPO Mashinostroyenia, the program focuses on ramjet propulsion technology. Russian engineers have analyzed Iranian flight-test data to resolve design issues. While no such missile has entered service, the technology poses a significant threat to U.S. Navy vessels in the Middle East amid deepening bilateral military ties.

Russia-Iran supersonic missile cooperation

• ▪Russia has secretly assisted Iran in developing supersonic cruise missiles under a covert program codenamed C430L that began in 2023, according to leaked documents reported by the Financial Times.
• ▪Russian and Iranian officials discussed the next stage of the C430L program as recently as June 2026, with Russia preparing technical reports for Tehran.
• ▪Russia's state arms exporter Rosoboronexport arranged the C430L program in coordination with NPO Mashinostroyenia, a Russian missile manufacturer sanctioned by the United States.
• ▪Rosoboronexport signed a formal contract for the C430L program with Iran's Ministry of Defence and Armed Forces Logistics in November 2023.

Ramjet propulsion technology transfer

• ▪By 2025, Russian engineers at NPO Mashinostroyenia analyzed Iranian flight-test data and technical materials to help Tehran resolve combustion, fuel supply, and aerodynamic design issues.
• ▪Although Iran has built and flight-tested a ramjet propulsion system, no supersonic cruise missile developed with Russian assistance has entered service as of September 2026.
• ▪The C430L program focuses on helping Iran develop ramjet propulsion technology, which enables cruise missiles to maintain flight at several times the speed of sound.

NPO Mashinostroyenia engineer visits

• ▪Senior NPO Mashinostroyenia engineers Alexander Dergachev, Alexander Chebakov, and Yuri Prokhorchuk repeatedly traveled to Iran in 2023 to assist with the missile program.
• ▪In April 2025, Rosoboronexport proposed sending a delegation of Russian specialists to Iran to act as consultants, requesting that Tehran answer technical questions beforehand.
• ▪Vladislav Kuzmichev, head of Rosoboronexport's department of defense technologies and space, accompanied Russian engineers to Iran and negotiated the C430L contract.

US naval threat implications

• ▪Supersonic cruise missiles developed under the C430L program are intended for anti-ship and land-attack missions, posing a threat to United States Navy vessels in the Middle East.
• ▪The high speed and low-altitude flight capabilities of supersonic cruise missiles reduce the detection and interception time available to air and missile defense systems.

Russia-Iran military alliance

• ▪Iran previously supplied Russia with Shahed attack drones for use in Ukraine and assisted Moscow in establishing domestic production facilities for the drones.
• ▪Western and Ukrainian officials have accused Russia of providing Iran with satellite imagery, drone support, and weapons components during Iran's conflict with the United States and Israel.
• ▪Russian President Vladimir Putin met Iranian President Masoud Pezeshkian at the Shanghai Cooperation Organisation summit in Kyrgyzstan on September 1, 2026, pledging continued economic cooperation.

4 sources