The Kremlin said on Wednesday the use of U.S.-made military hardware by pro-Ukrainian fighters who conducted a raid on a Russian border region this week was testament to the West's growing involvement in the Ukraine conflict.

The Russian military said on Tuesday it had routed militants who attacked the Russian border region of Belgorod with armoured vehicles the previous day, killing more than 70 "Ukrainian nationalists" and pushing the remainder back into Ukraine.

It said it had destroyed four armoured vehicles and five pick-up trucks to repel what was one of the largest incursions onto Russian soil from Ukraine since Moscow launched what it calls its "special military operation" in Ukraine 15 months ago.

Footage of some of the destroyed vehicles released by the Russian defence ministry showed U.S.-made military hardware such as Humvee military trucks.

Reuters was able to confirm the location of damaged vehicles and surrounding details shown in the video, though could not verify the date it was filmed.

Russian Defence Minister Sergei Shoigu promised on Wednesday that Moscow would respond to any more cross-border raids by Ukrainian militants swiftly and "extremely harshly."

"It is no secret for us that more and more equipment is being delivered to Ukraine's armed forces," Kremlin spokesman Dmitry Peskov told reporters when asked about the fighters' use of Western-made hardware.

"It is no secret that this equipment is being used against our own military. And it is no secret for us that the direct and indirect involvement of Western countries in this conflict is growing by the day. We are drawing the appropriate conclusions."

 

Military analysts said

this week's two-day incursion could force the Kremlin to divert troops from front lines as Kyiv prepares a major counteroffensive it hopes will eventually defeat what it casts as an unprovoked Russian war of conquest.

Reuters verified the location of damaged vehicles shown in the defence ministry video as Graivoron, a Russian town about 5 kilometres (3 miles) from the border with northeastern Ukraine.

Buildings, fencing, the road layout, terrain and the tree lines matched satellite imagery of the area and corroborating videos from the same location.

The United States, Ukraine's biggest military supplier, has played down reports that American-made military hardware was used in the raid.

U.S. State Department spokesperson Matthew Miller said on Tuesday he was "sceptical at this time of the veracity of these reports.

"As a more general principle ..., we do not encourage or enable strikes inside of Russia and we've made that clear. But as we've also said, it's up to Ukraine to decide how to conduct this war."

Ukraine's government denied any role in the raid, which has been claimed by two anti-Kremlin armed groups made up of Russian nationals fighting for Kyiv against their compatriots. They include far-right figures among their leadership. (Reporting by Reuters reporters; writing by Andrew Osborn; editing by Mark Heinrich)