Boris Johnson promises massive sanctions to ‘hobble’ Russian economy

PM says we will not just look away' and Putin's barbaric adventure' in Ukraine must end in failure

• Russia-Ukraine crisis: live updates

Boris Johnson has said that a vast invasion is under way, by land, by sea and by air" in Ukraine, as he promised to impose massive" sanctions that would hobble" the Russian economy.

Speaking as world leaders scrambled to respond to the attacks that began in the early hours of Thursday morning, the UK prime minister said Russia had attacked a friendly country without any provocation and without any credible excuse".