Russia deployed its first regiment of hypersonic nuclear-capable missiles on Friday, the Defence Ministry said, a move which President Vladimir Putin has boasted puts his country in a class of its own.
Defence Minister Sergei Shoigu has informed Putin of the deployment, his ministry said in a statement, which did not say where the missiles were located.
The new system, called Avangard, comprises a hypersonic glide vehicle which is designed to sit atop an intercontinental ballistic missile, one of several new types of weapons touted by Putin as being ahead of their time.
Putin has said that Russia's new generation of nuclear weapons can hit almost any point in the world and evade a U.S.-built missile shield, though some Western experts have questioned how advanced some of the weapons programmes are.
Putin said on Tuesday the Avangard system could penetrate both existing and any future missile defence systems.
"Today, we have a unique situation in our new and recent history. They (other countries) are trying to catch up with us. Not a single country possesses hypersonic weapons, let alone continental-range hypersonic weapons," said Putin.
Hypersonic glide vehicles are boosted aloft on a rocket to heights of between 40 km (25 miles) and 100 km (62 miles) above the earth before detaching to glide along the upper atmosphere towards their target, say researchers.
Control surfaces on glide vehicles mean they can steer an unpredictable course and manoeuvre sharply as they approach impact. They also follow a much flatter and lower trajectory than the high, arching path of a ballistic missile.
That makes them much harder to detect early with radar, giving missile defences less time to respond, say researchers.