US President Joe Biden confirmed Monday that Russia has used a hypersonic missile in Ukraine.

Commenting on Moscow's use of advanced weapons in its ongoing military operation in Ukraine, Biden described the Russian hypersonic Kinzhal missile as "almost impossible to stop."

During a meeting with representatives of the business sector, Biden pointed out that the hypersonic Kinzhal missile is "a consequential weapon ... but with the same warhead on it as any other launched missile. It doesn't make that much difference except it's almost impossible to stop it. There's a reason they're using it."

Last Saturday, Russian Defense Ministry Spokesperson, Igor Konashenkov, confirmed that the Russian army had used the missile to destroy an underground military depot in western Ukraine.

A "head-scratcher" for Pentagon

Earlier, a US military official acknowledged that “It’s a bit of a head-scratcher, to be honest with you, because it’s not exactly clear why — if it’s true — why would you need a hypersonic missile fired from not that far away to hit a building?”

For his part, Amir Bohbot, Israeli website Walla!'s military commentator and reporter, commented on the weapon's use, calling it "one of the secret weapons and terror missiles of the Russian army."

The Kinzhal, Bohbot said, is a ballistic air-to-surface missile capable of reaching speeds five times the speed of sound, whose range is 2,000 km, and its main purpose is to strike warships and sensitive infrastructure like air defense systems. 

Russia tested the hypersonic Kinzhal missile for the first time during military exercises in Syria last February.

It is noteworthy that Russian President Vladimir Putin unveiled the Kinzhal missile in March 2018.