Vladimir Putin has said Russia will start mass-producing a new hypersonic, non-nuclear ballistic missile it fired at Ukraine on Thursday.
In a televised address last night, President Putin said the intermediate-range missile, which he called Oreshnik, the Russian word for hazel tree, had been used in a strike on the Ukrainian city of Dnipro in response to US and UK weapons being used by Ukraine to strike deep inside Russia.
Mr Putin, whose land, air and sea invasion of its smaller neighbour reaches the three-year mark in February, boasted about the missiles, saying "no one in the world has such weapons".
He said Moscow would start producing them on a mass scale, while acknowledging other countries could get hold of them "sooner or later".
What do we know about Putin's new weapon?
Intermediate missiles have a range of 3,000-5,500 km (1,860-3,415 miles), which would enable them to strike anywhere in Europe or the US from Russia.
Sky News military analyst Sean Bell notes this is not a new capability for Russia.
While the missile which hit Ukraine on Thursday didn't have a nuclear warhead, Mr Putin said it is so powerful that using several fitted with conventional warheads in one attack could be as devastating as a strike with nuclear weapons.
Detailing the missile's alleged capabilities during a previous address on Thursday, Mr Putin claimed air defences wouldn't be able to destroy it as it travels 10 times the speed of sound (Mach 10).
According to Ukrainian military officials, the missile which hit Dnipro had reached a speed of Mach 11 and carried six non-nuclear warheads, each releasing six submunitions.
Mach is a measurement of supersonic speed. Mach 11 equals about 13,600 kph.
Bell said the Oreshnik has six to eight separate warheads and each of those can be individually programmed, meaning they can strike different targets at once.
Normally, he said, the missile would be designed for nuclear weapons, but it can carry conventional ones too.
While noting how their speed makes them hard to be intercepted, Bell pointed to how Mr Putin's claim that no system can shoot them down was also made in relation to previously-used Mach 8 missiles - which he says the West has been shooting down regularly.
"It's difficult to shoot them down when they're in space, but they inevitably slow down a lot as soon as they hit the Earth's atmosphere and that's when they become more vulnerable," he said.
Bell explained how air density slows missiles down, increasing their chances of being intercepted.
The way intercontinental missiles work is by "going ballistic" and "into space" so they can travel faster.
"You just spend longer in space, so it just makes them really difficult to shoot down," he said.
(c) Sky News 2024: What we know about the new weapon used by Russia in Ukraine