Deep secrecy has surrounded tests and designs of the Zircon, which Putin claims is unmatched by any Western missile.
Express.co.uk: Russia to fire new hypersonic missile in test of Putin’s weapon of choice to destroy US
Russia's MiG-31 supersonic interceptor jets carrying hypersonic Kinzhal (Dagger) missiles fly over Red Square during the Victory Day military parade in Moscow on May 9, 2018.
