The United States has intensified pressure on the United Kingdom to increase its defence spending, with a senior US official expressing concerns that Britain’s commitment to meeting NATO defence targets is faltering. Speaking anonymously ahead of the NATO summit in Ankara, the official said the UK’s recently released defence investment plan “shows no clear path” to achieving the alliance’s target of 3.5 percent of GDP on defence expenditure by 2035.

This criticism echoes broader unease among military leaders and politicians across the UK. They argue that the government has yet to present a definitive strategy for reaching NATO’s 3 percent spending benchmark, let alone the higher 3.5 percent goal agreed at the previous summit in The Hague. The official noted that the UK is also likely to miss capability targets related to equipment and weapon commitments pledged to NATO.

A second NATO source warned that the UK would soon determine whether it has done enough to satisfy US demands for burden-sharing, particularly from former President Donald Trump, who has repeatedly urged European allies to increase their defence contributions. This official highlighted the dual imperative of safeguarding the UK’s population of approximately 70 million and fulfilling alliance-wide commitments toward the collective security of over one billion citizens.

Labour leader Sir Keir Starmer, scheduled to attend the summit and sit beside President Trump at the North Atlantic Council meeting, has yet to outline a clear trajectory for increasing defence expenditure. Although the two leaders are not expected to hold a formal bilateral meeting during the summit, informal discussions could take place.

Downing Street has dismissed claims that the UK is falling behind on its defence spending obligations. An official spokeswoman refuted the criticism voiced by US NATO ambassador Matthew Whitaker, who recently stated that “many allies are lagging behind” and that President Trump expects immediate action. The spokeswoman emphasized that the UK “has always met its NATO spending commitments” and remains among the alliance’s leading defence spenders. She also highlighted that the government had delivered the most significant sustained boost to defence funding since the Cold War.

However, the ten-year defence investment plan published last week only provides detailed funding for the next four years. The plan is deemed affordable only if the UK raises defence spending to 3.5 percent of GDP by 2035, a target that would require an additional £25 billion annually. Andy Burnham, anticipated to become prime minister later this month, will be tasked with setting out the path for future defence investment in next year’s spending review. Uncertainty remains about whether the new government will commit to the 3 percent or 3.5 percent spending objectives, leaving ministers and military officials unclear about the UK’s long-term commitments.

At a pre-summit press conference in Ankara, NATO Secretary-General Mark Rutte called on member states to present “clear, concrete and credible plans” to meet the alliance’s goal of 5 percent combined defence and related spending by 2035. He noted that the evidence presented thus far was “impressive,” underscoring the importance of fulfilling collective responsibilities to maintain security across the alliance.