"This requires an adequate response also from our forces, who will take the corresponding decisions from the military point of view," said the Kremlin spokesman Dmitri Peskov.
CNN reported that London has supplied Ukraine with Storm Shadow missiles, giving Ukrainian forces one of the most sought-after weapons on the eve of their counter-offensive.
The Storm Shadow missiles, jointly developed by the UK and France, have a range of more than 250 km, slightly less than the ATACMS missiles the US has so far refused to send to Ukraine.
Map showing the range of British-supplied Storm Shadow long-range cruise missile that'll be used by Ukraine, taking into account their possible use on objects not only in Crimea, but also in the rest of Russia. pic.twitter.com/quSloE0dsD
According to U.S. military sources, the Storm Shadow missiles will make the difference in the conflict's balance of forces, providing Ukraine with military capabilities that it has been requesting since the start of the war.
A Western official told CNN that London has received assurances from the Ukraine that these missiles will be used only inside "sovereign" Ukrainian territory and will not be launched into Russian territory.
The deployment of these new weapons comes as the Ukrainian Army prepares to launch a counter-offensive against Russian forces that control four regions in the Donbas.