A dramatic rise in Ukrainian attacks on Russian oil refineries has sent gasoline prices in Russia to record highs, despite the government banning petrol exports to cope with the crunch.

NATO allies and Ukraine are working together to make sure security guarantees for Ukraine are at such a robust level that Russia will never try to attack again, NATO chief Mark Rutte said on Friday, adding that Europe and the United States would be involved in providing them.

Spurred by its existential fight against Russia — and limited military assistance from Western allies — Ukraine has fast become a global center for defense innovation.