Republican presidential hopeful Donald Trump on Monday suggested a diminished role for the United States in the NATO military alliance.
"We certainly can't afford to do this anymore," Trump told the Washington Post editorial board in an interview.
"NATO is costing us a fortune, and yes, we’re protecting Europe with NATO, but we’re spending a lot of money."
In an interview later Monday with CNN, Trump clarified that he would "keep NATO" but pay less.
The US has long called on NATO allies to step up their military spending as part of the alliance, but if US contributions to the North Atlantic alliance were cut, it would mark a significant change in US foreign policy with longstanding support for European allies among politicians of both major US political parties.
The US accounted for 72 per cent of total NATO defence expenditures last year. NATO countries have pledged to increase their military spending to 2 per cent of gross domestic product, but only five member states currently meet that target: Britain, Estonia, Greece, Poland and the US.
In a series of Republican debates, Trump has repeatedly bemoaned the fact that the US plays an outsized role in global defence, including in South Korea, Japan and the Middle East.
Trump leads the Republican contest to become the party's candidate in November presidential elections, although much of the party establishment has opposed his candidacy.