Russian Foreign Ministry spokeswoman Maria Zakharova said that Moscow will strike British targets inside and outside Ukraine if British weapons are used to strike Russian territory.

This comes after Ukraine and Britain signed in April a framework agreement for cooperation in the field of defence and weapons production, as part of Ukraine’s military effort to build a local military industry

British Foreign Secretary David Cameron had emphasised that Ukraine is free to use the weapons supplied by Britain to launch attacks inside Russia.
This prompted Russia to summon the British ambassador in Moscow, Nigel Casey, to lodge an official protest.