Theresa May will tell the head of Nato that other members of the alliance must pay their way amid concerns that Donald Trump could withdraw his support.

The Prime Minister will on Wednesday meet Jens Stoltenberg, the Secretary General of Nato, in Downing Street for the first time since Mr Trump's election.

During the US election campaign Mr Trump criticised Nato members for failing to meet their obligation to spend 2 per cent of national income on defence. He suggested that under his presidency the US may refuse to come to their aid unless they "pay their bills".

Britain has also raised repeated concerns that other members of Nato are failing to spend enough on defence while enjoying the protection of the alliance.