Doug Richardson, the editor of Jane's Missiles and Rockets, said it might have been a Standard interceptor, the anti-missile weapon which is fitted to the US Navy's Aegis guided-missile cruisers as part of the American missile defence programme.
He said: "It's a solid propellant missile, you can tell from the efflux [smoke] but they're not showing enough of the tape to show whether it's staging [jettisoning its sections]."
Robert Ellsworth, the former US Deputy Secretary of Defense, said it was "pretty big" but "not a Tomahawk" cruise missile.