Russia has reportedly been quietly helping Iran build advanced supersonic cruise missiles, a development that could give Tehran a new class of weapon capable of threatening U.S. warships.
According to a report from The Financial Times, a covert program codenamed C430L was launched in 2023, enlisting some of Russia's top missile specialists to assist Iran in developing this new capability. The program is centered on ramjet propulsion technology, which allows cruise missiles to sustain speeds several times faster than the speed of sound.
"This is the transfer of a highly strategically sensitive military technology from Russia that the Iranians have wanted to acquire for decades," said Fabian Hinz, an expert on Iranian missiles, in an interview with the publication.
The program was arranged by Russia's state arms exporter Rosoboronexport and missile developer NPO Mashinostroyenia. Russian engineers reportedly made several trips to Iran before a contract was signed with Iran's Ministry of Defense and Armed Forces Logistics in November 2023.
In April 2025, Rosoboronexport proposed sending around two dozen specialists to Iran for technical consultations under C430L. The planned mission was tied to analyzing Iran's propulsion system, with Moscow asking Tehran to provide flight-test telemetry data before the engineers' visit.
Iran has developed and flight-tested a ramjet propulsion system, but there is currently no evidence that a Russian-assisted supersonic cruise missile has been deployed.
"For the Iranians, this would give them a qualitatively new strategic weapon system that could threaten US Navy vessels," said Jim Lamson, a former CIA Iran military analyst now at the James Martin Center for Nonproliferation Studies.
