Theresa May will visit Donald Trump in spring this year following preparatory December meetings between key staff from Downing Street and the United States president-elect's team, a Number 10 source said.

The Prime Minister's joint chiefs of staff Nick Timothy and Fiona Hill travelled to the US last month to build links with Mr Trump's team.

The mission was part of Mrs May's efforts to build a relationship with the controversial tycoon ahead of his inauguration on 20 January.

The source said: "This was part of a process leading towards the PM's first visit with President-elect Trump.

"During the second phone call with President-elect Trump, the Prime Minister suggested it would be a good idea for key staff from both teams to meet. President-elect Trump agreed this would be useful.

"We are pleased to have been able to make that happen and the Prime Minister looks forward to visiting the new president in the spring."

Early last month Mrs May praised Mr Trump as "very easy to talk to", despite having criticised him during the US elections.

Donald Trump's inauguration: All you need to know

The Prime Minister’s compliment formed part of her drive to build relations with the new administration, after a rocky start in which she and other senior Tories tried to move on from previous derogatory comments.

Speaking during a visit to Bahrain, Ms May said: "He is somebody who very much values the relationship he has with the UK."

During his campaign, when Mr Trump called for a ban on Muslims entering the US and claimed parts of London were no-go areas for the police, Ms May as Home Secretary said: "I just think it shows he does not understand the UK."