President Volodymyr Zelensky says the use of weapons, including Western-supplied arms, on Russian territory is "a question of time", in order for Ukraine to defend itself, speaking at a summit in Sweden. Washington gave the green light on Thursday for Ukraine to use US weapons to defend its Kharkiv region on the border with Russia, overcoming previous concerns that authorising such strikes could drag NATO into a direct conflict with Russia. Zelensky has been touring European capitals in recent days to appeal for more military aid for his army, which has been ceding ground to relentless Russian attacks in the recent weeks. IMAGES AND SOUNDBITES