British Prime Minister Keir Starmer is expected to face renewed pressure from the United States at this week’s NATO summit after Washington urged member nations that are falling behind on defense spending to accelerate their commitments.

The annual gathering in Ankara comes as NATO allies continue to focus on strengthening military readiness amid ongoing security challenges in Europe and beyond.

U.S. calls for faster action

Speaking ahead of the summit, U.S. Ambassador to NATO Matt Whitaker said some alliance members are not increasing defense spending quickly enough. He praised countries such as Poland and the Baltic states while urging others to move more rapidly toward NATO’s long-term spending goals.

Last year, NATO members agreed to work toward spending at least 3.5% of GDP on core defense by 2035, alongside broader security-related investments totaling 5% of GDP.

UK spending plan under scrutiny

The British government recently unveiled its latest defense investment plan, which includes an additional £15 billion in funding. Under the current plan, UK defense spending is expected to rise gradually from around 2.6% of GDP in 2027 to 2.7% by 2030, with an ambition to reach 3% during the following parliamentary term.

Some NATO partners have questioned whether that timeline is ambitious enough given the alliance’s evolving security priorities.

Leadership uncertainty adds questions

The summit also comes amid political uncertainty in the United Kingdom following speculation about future leadership changes. Defense Secretary Dan Jarvis has called for the government to demonstrate a clearer path toward NATO’s long-term spending targets, arguing that future budgets should reflect those commitments.

His comments highlight growing pressure on the UK to reassure allies that it intends to meet the alliance’s expectations.

Russian military activity remains a concern

The debate over defense spending follows a recent incident in which British F-35 fighter jets intercepted a Russian military aircraft that approached HMS Prince of Wales in the Norwegian Sea. According to the UK’s Ministry of Defence, the Russian aircraft repeatedly flew near the carrier before being escorted away by Royal Air Force jets.

The encounter underscores why many NATO members continue to prioritize increased military investment and readiness.

Focus shifts to Ankara

As leaders gather in Turkey, defense spending is expected to be one of the summit’s central topics alongside continued support for Ukraine, collective security and the alliance’s long-term strategy.

While discussions are likely to remain behind closed doors, the outcome could influence how quickly member states move toward meeting NATO’s ambitious defense spending goals in the years ahead.