Donald Trump has claimed in the US possesses “advanced” nuclear-powered cruise missiles, in a suggestion rapidly dismissed by experts.
He tweeted: “The United States is learning much from the failed missile explosion in Russia. We have similar, though more advanced, technology. The Russian ‘Skyfall’ explosion has people worried about the air around the facility, and far beyond. Not good!”
The post raised a number of possibilities: that Mr Trump had casually revealed the existence of a secret US nuclear programme; that he had misunderstood the nature of his country’s nuclear arsenal; or that the claim was a baseless brag.
America explored the development of a nuclear-ramjet-powered projectile during the Cold War but the scheme – Project Pluto – was abandoned for being unstable and dangerous, given it would exhaust radiation and cause massively damaging shockwaves while flying at low altitude.
Joe Cirincione, a US nuclear weapons and policy expert, said on Twitter: “This is bizarre. We do not have a nuclear-powered cruise missile program. We tried to build one, in the 1960’s, but it was too crazy, too unworkable, too cruel even for those nuclear nuts Cold War years.”
On Monday, thousands of people attended the funerals of the scientists killed while testing a nuclear-powered engine in the Arkhangelsk region four days earlier.
Nuclear agency Rosatom said the explosion occurred while the engineers were testing a “nuclear isotope power source” for a rocket engine. Authorities in nearby Severodvinsk, a city of 183,000, reported a brief spike in radiation levels after the explosion.
Russian media speculated that the device being tested was the Petrel nuclear-powered cruise missile announced by Vladimir Putin in March 2018.
Mr Putin claimed the weapon would have an unlimited range and could fly fast enough to evade defence systems. The president also claimed the missile had successfully undergone initial testing but observers believed this was unlikely.
Additional reporting by AP