Head of NATO, Jens Stoltenberg, says Donald Trump’s suggestion the US would not protect allies failing to spend enough on defence would undermine European security.

Mr. Stoltenberg also suggested it put US and European troops at greater risk.

Trump said he had told allies he would encourage Russia to attack any NATO member that failed to meet the alliance’s target of 2 per cent of their GDP.

Members of NATO commit to defend any nation in the bloc that gets attacked.

President Joe Biden called Trump’s comments appalling and dangerous.

He said his predecessor intended to give Russian President Vladimir Putin a green light for more war and violence.