Donald Trump berated his allies over military spending and claimed Nato "benefits Europe far more than the United States".

His comments on the eve of a Nato summit in Brussels set the stage for a tense meeting with European leaders.

Writing on Twitter the US president said: "The United States is spending far more on Nato than any other Country. This is not fair, nor is it acceptable. While these countries have been increasing their contributions since I took office, they must do much more."

Mr Trump said many countries were "nowhere close" to their commitment to spend two per cent of GDP on defence, and "by some accounts the US is paying for 90 per cent of Nato".

He also attacked the European Union for having a trade surplus with the US and "big Trade Barriers on US goods," adding: "No!"

It was the latest criticism of Nato by the US president and raised fears among European diplomats that the Brussels summit, starting on Wednesday could be rancorous.