The PM also hinted that sea and air security guarantees will be now be a priority for the peacekeeping mission ahead of ground troops
Vladimir Putin will face “severe consequences” if he attacks UK troops in Ukraine, Sir Keir Starmer has warned as plans for a “coalition of the willing” to keep the peace took a step forward.
The Prime Minister assembled the representatives of 31 different countries at a military base in Hertfordshire to begin the planning for a multinational force which could provide security guarantees to Kyiv as part of a future peace deal.
He said that operations at sea and in the air would be the initial priority, as well as building up the strength of Ukraine’s own armed forces so it is better able to defend itself from Russia.
Speaking to officers at Northwood Headquarters, the UK’s main centre of military planning, Starmer warned that any deal to end the invasion of Ukraine must be “defended”, adding: “We know one thing for certain, which is a deal without anything behind it is something that Putin will breach. We know that because it happened before. I’m absolutely clear in my mind it will happen again.”
The Prime Minister insisted that Putin would not be able to wield a veto over the make-up of any peacekeeping force, saying: “What we’re clear about is that Ukraine needs to be secure and needs to be sovereign. And if you’re sovereign, that means that you decide for yourself what defence capability you have. You don’t let the person who’s invaded your country tell you what defence capability that you have.”
Asked by The i Paper if he was willing to confront Russia military in the event of a breach of a ceasefire, Starmer replied: “The point of the security arrangements is to make it clear to Russia there’ll be severe consequences if they are to breach any deal.”
He added: “This is why it will require a US component, because it needs to be clear to Putin that there will be severe consequences if he breaches the lines.”
Britain's Prime Minister Keir Starmer and John Healey, Secretary of State for Defence, look at a Ukraine map as they visit a military base to meet planners mapping out next steps in the Coalition of the Willing in Northwood, London, Britain, March 20, 2025. Alastair Grant/Pool via REUTERS
Prime Minister Keir Starmer visits a military base to discuss next steps on the Coalition of the Willing in Northwood, London (Photo: Alastair Grant/Pool via REUTERS)
The arrangements would be similar to those already in place in Eastern European countries such as Estonia, where the UK has long maintained a military presence, he suggested.
The talks were led by the UK and France, as well as Ukrainian representatives, with other countries attending including Germany, Poland, the Netherlands, Denmark, Sweden Canada, Australia, New Zealand, Romania, Spain, Italy, Turkey, Albania and the Baltic states.
Starmer said that talks on the peacekeeping force were being “broken out into different areas”, specifying: “We’re looking at the sea in one scenario, the sky, obviously land and borders and regeneration.”
He praised the strength of the Ukrainian military, which he called “amongst the strongest now in Europe” because of its “frontline experience”, and added: “We’re not talking about something that replaces the capability, we’re talking about something that reinforces that and then puts around it capabilities in relation to air, water and sea and land.”
The Prime Minister’s comments will be taken as a hint that allies’ plans are moving away from a focus on “boots on the ground” in large numbers with an emphasis instead on providing back-up to a ground force built around Kyiv’s own troops.
The proposed force is now significantly smaller than the 30,000 troops that Starmer reportedly pitched to Donald Trump during their White House meeting last month.
Earlier this week,The i Paper revealed that British Special Forces had been put on standby to head to Ukraine for the proposed peacekeeping mission as part of a smaller, more specialised military group on the ground.
Starmer said that any move towards peace could come in multiple stages, with an initial limited ceasefire to be followed later by a full and permanent cessation of hostilities.
And he welcomed the EU’s moves to creating a more powerful military alliance, suggesting that the UK remains keen to deepen co-operation with Brussels. The Prime Minister said: “I’m speaking to the president of the [European] Commission pretty well all the time about their thinking and how we take this forward together.”
The UK Government has been careful not to criticise Donald Trump for the work he has done to try and get a deal with Putin, even as European allies push to provide security backing for Ukraine that could allow it to continue fighting even without US support.