President Donald Trump has touched down on British soil for the start of his divisive four-day visit that has sparked outrage in Parliament and mass protests around the country.
The President and First Lady waved at cameras from the steps of Air Force One as they disembarked at Stansted Airport on Thursday evening.
Mr Trump appeared cheerful and calm as he descended onto the tarmac after flying in from Brussels fresh from a fierce row with American allies at a Nato summit.
The couple then boarded a helicopter which took them to Winfield House in Regent's Park - the official home of the US Ambassador.
This UK trip – his first official one since becoming president – has been dogged with plans for tens of thousands of protesters to march through central London in condemnation of his controversial leadership.
Politicians, including Labour leader Jeremy Corbyn, have repeatedly called for the invitation to be retracted - particularly in light of recent stories about child migrants being separated from their families in the US.
And the fact that the visit, which was arranged at the request of the Prime Minister, is expected to leave taxpayers with a police and security bill of up to £10 million has done nothing to quell public anger.
Theresa May will host Mr Trump, and his wife Melania, at a lavish dinner at Blenheim Palace before the they spend the night at the US ambassador's official residence in Regent's Park.
Mr Trump will then join Mrs May at a military base on Friday to observe a joint counter-terrorism exercise involving UK and US special forces.
The two leaders will hold talks at the Prime Minister's country residence of Chequers where Russia, Brexit and the Middle East will top the agenda.
Mr Trump will then travel to Windsor Castle to meet the Queen before heading to Scotland, where he will spend time on his golf course, ahead of travelling to Helsinki for a summit with Russian president Vladimir Putin.
He is expected to avoid areas in central London where the main part of the demonstrations will be and where an inflatable baby blimp of himself will be flying over Parliament.
Mr Trump raised eyebrows when he went out of his way to praise Boris Johnson after resigning as foreign secretary, while insisting it was up to the British people whether Mrs May remained in office or not.
Ahead of Mr Trump's visit, the PM said: "Our trade and investment relationship is unrivalled, we are the largest investors in each other's economies and every day a million British people go to work for US companies in the UK and a million Americans go to work for UK companies in the US.
"This week we have an opportunity to deepen this unique trading relationship and begin discussions about how we will forge a strengthened, ambitious and future-proof trade partnership.
"As two nations, we are safer, more prosperous and more creative when we work together and I am looking forward to this week's important discussions."
The US president used the Nato summit to launch fierce attack on Germany, saying it was "totally controlled" by Russia, as he ratcheted up demands for Nato allies to pay more for their collective defence.