US calls for increase in defence funding by NATO allies

U.S. President Donald Trump said NATO allies had no choice but to increase their military spending, repeating his demand that all those in the alliance meet the target of spending 2% of GDP a year on defence.

"The prime minister and I agree that our NATO allies must increase their defence spending - we've both been working very hard to that end," Trump told reporters on Tuesday after a meeting with Britain's Theresa May in London.

He added: "We expect a growing number of nations to meet the minimum 2% of GDP requirement. To address today's challenges, all members of the alliance must fulfil their obligations. They have no choice."

(With inputs from agencies.)