Keir Starmer has called for Europe to “step up” amid this “generational challenge” to the continent’s security right now.
The prime minister spoke to the media as pressure rises around the Ukraine war.
Starmer will head to Paris for an emergency summit with his European counterparts today, and is expected to travel to Washington to meet with Donald Trump next week.
The continent is scrambling to respond after the White House suggested it would only consult, but not directly include, Europe while negotiating a peace with Russia over the Ukraine war.
The new Trump administration has also called for Europe to be more responsible for its own security rather than relying on American support.
Speaking to broadcasters in Bristol, Starmer issued a call to action to his European neighbours. He said: “We’re facing a generational challenge when it comes to national security.
“Obviously, the immediate question is the future of Ukraine, and we must continue to put Ukraine in the strongest possible position whatever happens next, and to make sure that if there is peace – and we all want peace – that it is lasting.”
He added there is a “bigger piece here as well” noting that the challenge we face “isn’t just about the front line of Ukraine.”
“It’s the front line of Europe and of the United Kingdom. It’s our national security,” Starmer said.
Starmer confirmed overnight that he is ready to send peacekeeping troops to Ukraine if a deal is secured, despite concerns that the sector is already underfunded.
Labour has promised to increase spending its current rate of 2.3% of GDP to 2.5%, but it has not provided a clear timeframe for doing so.
The PM told broadcasters: “We are going through a strategic review of defence at the moment, which is looking at the challenges and the capability, and then we’ll set out that path.
“Part of my message to our European allies is that we’ve all got to step up on both capability and on spending and funding. Now, that includes the UK, which is why I’ve made that commitment to spend more.”
“Until we get a peace agreement, we must ensure Ukraine is in the strongest possible position,” he said.
The prime minister said: “We don’t know what’s going to happen next, and we need to have realistic and credible answers to how any ceasefire, how any peace agreement, will be lasting, just and enduring, because the last thing I want to see is a pause in the fighting that simply gives Putin the chance to come again, which is why it’s very important that we have these discussions.”
Starmer also downplayed concerns about a split between the US and Europe after vice-president JD Vance attacked the continent last week.
Amid reports he was looking to act as a bridge between Washington and the rest of Europe, Starmer said: “I think what the US wants to achieve is lasting peace in Ukraine that aligns precisely with what we want in the United Kingdom, what Ukraine wants and what our European allies want.
“What we now need to do is to make sure that we work together on a plan that could get us to that point.”