Starmer will call for more integration in Europe's defence industry when he addresses the Munich Security Conference after US President Donald Trump strained the unity of the NATO defence alliance with his desire to acquire Greenland from Denmark.
Trump has also consistently called on Europe to spend more on defence.
In his speech in Munich on Saturday, Starmer will say the US is an indispensable ally that has made an unparalleled contribution to Europe's security, but a more European NATO will help the continent shift from over-dependence on Washington.
"I'm talking about a vision of European security and greater European autonomy, that does not herald US withdrawal but answers the call for more burden-sharing in full, and remakes the ties that have served us so well," Starmer will say, according to speech extracts released by his office.
He will call for a new approach to defence procurement to avoid unnecessary duplication in the continent's defence industrial base, saying the current fragmentation meant Europe was a "sleeping giant".
Starmer has attempted to reset ties with the European Union since coming to office in 2024, four years after Britain exited the EU, and has also taken a leading role in co-ordinating European support for Ukraine against Russia's invasion.
However, talks for Britain to join the EU's SAFE defence fund broke down in 2025. Starmer has said he is open to joining a new version of SAFE, and is looking at other ways to work more closely with Europe on defence.
Starmer will say that "we are not the Britain of the Brexit years anymore", according to the speech extracts, adding that to turn inward would surrender control of Britain's security.
"There is no British security without Europe, and no European security without Britain", the extracts said.
Opening the Munich Security Conference, German Chancellor Friedrich Merz called for a stronger Europe to reset its ties with the United States, wanting Washington to "repair and revive trust".
Taking his cue from those warning the international rules-based order was about to be destroyed, Merz said: "I fear we must put it even more bluntly: This order, however imperfect it was even at its best, no longer exists in that form."
"In the era of great power rivalry, even the United States will not be powerful enough to go it alone," he said.
"Dear friends, being a part of NATO is not only Europe's competitive advantage. It is also the United States' competitive advantage. So let's repair and revive transatlantic trust together."
US Secretary of State Marco Rubio had also said transatlantic ties faced a "defining moment" in a rapidly changing world but struck a more conciliatory tone that contrasted with remarks by Vice President JD Vance in 2025.
At the same gathering of top security officials, Vance had attacked European allies in a speech that marked the start of a series of confrontations with Washington's partners, who face myriad threats from Russia's war in Ukraine to massive ructions in global trade.
"I think it's at a defining moment ... the world is changing very fast right in front of us," Rubio said before departing for Munich.
"The Old World is gone, frankly, the world I grew up in, and we live in a new era in geopolitics, and it's going to require all of us to re-examine what that looks like and what our role is going to be," he said.
"(The US is) deeply tied to Europe, and our futures have always been linked and will continue to be," said Rubio, who is a potential rival to Vance for the 2028 US presidential race.
"So we've just got to talk about what that future looks like."
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