The Prime Minister flies to Philadelphia, where she will address Republican Senators and Congress members, before meeting Donald Trump at the White House on Friday.

Mrs May, the first world leader to hold face-to-face talks with President Trump since his inauguration, has told MPs she is pleased to be able to meet him so early in his administration.

She wants to talk to the President about deepening the economic and commercial relationship between the two countries post-Brexit and signing a UK-US trade deal once the UK has left the EU.

Also on the White House agenda will be strengthening defence and security co-operation between the two countries and through NATO, countering the menace of Islamic State and creating conditions for peace in Syria.

While she is in Washington, Mrs May will also visit Arlington National Cemetery – where members of the British military who died fighting alongside US forces are buried – to lay a wreath at the Tomb of the Unknown Soldier.

The PM is flying straight to Philadelphia, where she will address the annual congressional Republican Retreat, becoming the first serving head of government or state from outside the US to do so.

As well as addressing the Republicans’ “congressional retreat”, she will also hold talks with Paul Ryan, Speaker of the House of Representatives, and Mitch McConnell, the Senate Majority Leader.