Russia secretly assisted Iran with advanced missile technology under the Russia-Iran missile program known as C430L, the Financial Times reported, citing leaked correspondence, travel records and military patents.
According to the FT, the program began in 2023 and continued into 2026, with a focus on a ramjet propulsion system designed to sustain cruise-missile flight at several times the speed of sound.
The newspaper said Iran had built and flight-tested the propulsion system. However, it found no evidence that a Russian-assisted supersonic cruise missile had entered operational service.
Russia’s state arms exporter Rosoboronexport arranged the programme with missile developer NPO Mashinostroyenia, the FT reported.
Russian engineers also travelled repeatedly to Iran before Tehran’s Ministry of Defence and Armed Forces Logistics signed a contract in November 2023.
By 2025, Russian specialists were analysing Iranian flight-test data and advising on fuel systems, combustion stability, air intakes and engine nozzles, according to records reviewed by the newspaper.
Fabian Hinz, a senior analyst with Conflict Armament Research, told the FT that the program involved the transfer of highly sensitive military technology that Iran had sought for decades.
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Jim Lamson, a former CIA military analyst focused on Iran, said the technology could give Tehran a new strategic weapon capable of threatening U.S. Navy vessels.
Supersonic cruise missiles combine high speed with low-altitude flight, which can shorten the reaction time available to air and missile defences, according to the FT report.
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A June 2026 Rosoboronexport letter showed that both sides were still discussing another phase of development it remained unclear whether that phase had begun.
The Kremlin, Rosoboronexport, NPO Mashinostroyenia and the Iranian government did not respond to Financial Times requests for comment.
