The Trump administration has issued a firm warning to NATO allies to increase defence spending immediately or face potential repercussions, ahead of the NATO summit set to begin in Ankara, Turkey. U.S. officials criticized several member states for lagging behind their pledged target of allocating 5 percent of GDP to defence by 2035, emphasizing urgent action rather than gradual progress.

Matt Whitaker, the U.S. ambassador to NATO, highlighted disparities among members, citing Poland, the Nordic countries, and the Baltic states as leading in defence commitments. By contrast, other members, including the United Kingdom, were described as falling short. Whitaker stressed that President Donald Trump expects all allies to not only commit to a sustainable trajectory toward 5 percent but to reach that goal as rapidly as possible.

This stance places NATO allies under significant pressure as Trump is reportedly considering a system of incentives and penalties linked to defence expenditure. Countries meeting or exceeding spending targets could receive preferential treatment in arms procurement and increased access to face-to-face engagement with the U.S. president. Conversely, the U.S. defense secretary has initiated a six-month review of the U.S. military posture in Europe, raising the possibility of troop withdrawals from nations that fail to meet spending benchmarks.

The impending NATO summit appears poised to be a critical forum where Trump is expected to outline specific consequences for countries that do not comply with these demands. The warning has already generated tensions, particularly with the United Kingdom. Earlier this week, UK Labour leader Sir Keir Starmer announced a £15 billion increase in defence spending, which would raise the UK’s military investment to approximately 2.7 percent of GDP by 2029, a figure significantly below the U.S. target. The funding will be partially sourced by cuts to planned infrastructure projects, and Starmer indicated that his Labour successor, Andy Burnham, may need to increase borrowing to cover around £5 billion of the package. Despite this boost, White House skepticism about Britain’s ability to meet NATO spending expectations remains high.

The summit will also offer the opportunity for President Trump to meet Ukrainian President Volodymyr Zelensky. The two leaders are expected to discuss prospects for ending the conflict in Ukraine, which continues to see slow but notable developments on the battlefield. Ukraine’s recent attacks on power infrastructure in Crimea and increased drone strikes near Moscow reflect a dynamic but largely stalemated front. A senior U.S. official acknowledged the urgency felt by Trump to seek resolution to the conflict.

Despite earlier public statements casting doubt on the United States’ commitment to NATO’s mutual defence clause, Article 5, sources at the summit suggest that the alliance has secured a renewed American pledge to collective defence. A forthcoming communique from NATO’s 32 leaders is expected to reaffirm an “ironclad commitment” to Article 5, underscoring the alliance’s unity amid ongoing challenges. The reaffirmation seeks to dispel concerns raised by Trump’s earlier remarks, which some interpreted as questioning the U.S. role in guaranteeing the alliance’s security.

As NATO leaders convene in Ankara, the summit’s outcomes will have significant implications for the future cohesion and defence posture of the alliance, against a backdrop of persistent geopolitical tensions in Europe and beyond.