Boris Johnson pledged new sanctions – including against the paramilitary Wagner Group seen as Russian President Vladimir Putin’s private army – as he urged allies to “step up” defensive support to counter the Kremlin’s invasion of Ukraine.

The Prime Minister is using a Nato emergency summit in Brussels on Thursday to commit to a new package to shore up Ukrainian forces, including 6,000 more missiles.

Speaking to broadcasters after landing in Belgium’s capital, Mr Johnson said: “Vladimir Putin is plainly determined to double down on his path of violence and aggression.”

Describing Mr Putin’s treatment of Ukrainians as “absolutely brutal”, he added: “We’ve got to step up. We’ve got to increase our support. We’ve got to tighten the economic vice around Putin, sanctioning more people today, as we are, sanctioning the Wagner Group, looking at what we can do to stop Putin using his gold reserves, and also doing more to help the Ukrainians defend themselves.

“We’re moving, really, from a programme of supporting resistance to supporting the Ukrainian defence of their own country.”

The Foreign Office is preparing to announce sanctions against 65 more entities and individuals, including Russian billionaire Eugene Shvidler and Galina Danilchenko, who was installed by Moscow as the mayor of occupied Melitopol in south-east Ukraine, the PA news agency understands.