Russian President Vladimir Putin, who unveiled the Kinzhal missile in 2018, has termed it "an ideal weapon" that is extremely difficult for missile defences to intercept.

"I congratulate the Ukrainian people on the historic event," General Mykola Oleshchuk said on Telegram. "Yes, we shot down the 'unparallelled' Kinzhal" missile.

The Ukraine Air Force said the missile was shot down with a Patriot air-defence system in skies over Kyiv at around 2:30 am on Thursday (2330 GMT Wednesday).

Ukraine appealed to its Western allies to help reinforce its air defence system as Russia pounded Ukraine energy infrastructure from the air over winter.

Mid-April, Ukraine received the first Patriots, seen as one of the most advanced US air defence systems.

President Volodymyr Zelensky has said the system would "significantly" strengthen Ukraine's defences against Russian strikes.