A sweeping review of the UK’s defence and security will begin next week, Sir Keir Starmer announced as he urged Nato members to increase military spending.

The review will set out a “road-map” to increasing the UK’s defence spending to 2.5% of gross domestic product, but no target date has yet been set to reach that target.

Sir Keir will meet fellow Nato leaders in Washington on Wednesday at a summit to mark the 75th anniversary of the alliance against a backdrop of global instability and the war in Ukraine.

The summit marks Sir Keir’s debut on the world stage, and on Wednesday afternoon he will visit the White House for talks with Joe Biden.

But the summit comes with Mr Biden mired in domestic political difficulties and with the prospect of Donald Trump replacing him in the White House after November’s election and adopting a much more sceptical approach to Nato.

Mr Trump has repeatedly called for European nations to ramp up defence spending if they want to continue to enjoy the protection of the US as part of the alliance.

Sir Keir will hope he can persuade more countries to meet the alliance’s target of spending 2% of GDP on defence, even as he faces pressure to spell out more details of his own 2.5% commitment.

Before the election defeat, Rishi Sunak had committed to reach 2.5% by 2030 at a total cost of £75 billion over six years.

The strategic defence review being launched by Sir Keir will not necessarily follow that timetable but will instead set out how the Labour government will reach that goal.

The Prime Minister said: “There is no more important duty for me as Prime Minister than keeping the people of our country safe.

“At a time when we face multiple threats at home and abroad, we must make sure we are ready to defend ourselves. That’s why I have immediately ordered a root-and-branch review that will secure Britain’s defences for the future.

“Working with our most important partners around the world, our strategic defence review will make sure the UK is sending a clear message to those who seek to undermine peace and democracy – you will not succeed.”

Officials said preparatory work for the review had already been carried out by Defence Secretary John Healey.

The review will determine the future defence posture of the UK, the capabilities needed and chart a path to the “cast iron commitment” on 2.5%.

Mr Healey said: “Our government’s first duty is to keep the country safe. That’s why we will increase defence spending and launch a strategic defence review to ensure we have the capabilities needed to protect the UK now and in the future.

“The review will also set out defence reforms to secure faster procurement and better value for money.”

The review will put a “Nato-first” policy at the heart of the UK’s plans and will be drawn up with input from allies, experts and the defence industry.

The review will respond not just to Russia’s invasion of Ukraine but also the instability in the Middle East and the rise of authoritarian countries.

Mr Healey and Foreign Secretary David Lammy are also in Washington for the summit, along with European relations minister Nick Thomas-Symonds who will be seeking to build bridges with EU states.

Labour Party Conference 2023
David Lammy and John Healey are also in Washington (Stefan Rousseau/PA)

It will also mark Sir Keir’s wife Victoria’s introduction to the international summit circuit, where she will take part in a series of engagements with other leaders’ wives and husbands.

Sir Keir’s first day at the summit will coincide with England’s Euro 2024 semi-final against the Netherlands.

Football fan Sir Keir hopes to watch some of the game, although he may struggle to watch the whole match given the demands of the summit and the visit to the White House – particularly if Gareth Southgate’s men persist with needing extra time in their knockout games.

Support for Ukraine will be at the top of the agenda for the summit, with Volodymyr Zelensky in attendance.

It will also be the key talking point when Mr Biden hosts Sir Keir at the White House.

The leaders will also have the opportunity to discuss UK-US cooperation on advancing a free and open Indo-Pacific, reaching a ceasefire and hostage release deal in Gaza, Iran and the threat of Houthi rebels to commercial shipping.

The gathering in Washington comes just days after a Russian missile struck a children’s hospital in Kyiv.