President Donald Trump is arriving at a NATO summit in Ankara, Turkey, carrying fresh frustration with several European allies over their responses to recent US-led military operations against Iran. His irritation opens a new front in his long-running push to pressure the alliance over burden-sharing, and it threatens to overshadow a meeting meant to concentrate on defence spending, Ukraine and NATO's long-term strategy towards Russia.

According to US Ambassador to NATO Matthew Whitaker, Trump remains "disappointed" both with allies that refused US forces the use of military bases or overflight rights during the operation and with political statements criticising the strikes. Among his most prominent critics is Spain, whose Prime Minister Pedro Sánchez branded the US action against Iran "illegal, absurd and cruel". Trump has said he is attending largely because of his relationship with Turkish President Recep Tayyip Erdoğan, while renewing his criticism of allied defence spending. Whitaker also outlined a vision of "NATO 3.0", urging members to boost spending and war-fighting capabilities to reduce reliance on the United States.