Labour leader Jeremy Corbyn has described as "very strange behaviour" President Trump's statement today that it would be possible to do a trade deal with the UK, despite telling the Sun newspaper it would be difficult.

Mr Corbyn also said it was a "bit odd" to offer to do a trade deal with the UK, so soon after imposing tariffs on steel and aluminium.

The Labour leader called on the government to prioritise retaining trade relationships with the EU, before looking at trade relationships with other countries.

He also described President Trump's visit to the UK as "an odd one" and said he wished there'd been an opportunity for him to "understand something about our society."

"He hasn't met any ordinary people in Britain at all," he said.

Mr Corbyn added that Mr Trump's criticism of London Mayor Sadiq Khan was "completely unacceptable" and "quite without precedent".

Image source, Alex Mitchell

This picture was taken in central London, near Trafalgar Square, by Alex Mitchell, external.

Donald Trump is on his way to Windsor to meet the Queen, the BBC understands.

His helicopter, Marine One, has left the home of the US ambassador in London where Mr Trump and his wife Melania have been staying.

The flight to Windsor is expected to take about 10 minutes.

Tom Burridge
BBC Correspondent

Trafalgar Square is pretty full but there is quite a good atmosphere, it's relaxed and fun.

There are some speeches from the TUC and charities such as an organisation against racism.

It's quite remarkable - a good chunk of the city has essentially been shut down.

PoliticsHome editor Kevin Schofield says that despite President Trump singing "a completely different tune" during the press conference with Theresa May, people will remember his damaging Sun interview when they think back to his first visit to the UK as US president.

Trafalgar Square is approaching capacity and police and some protesters may be asked to move, the Metropolitan Police has said.

Image source, Chris Jackson/Getty Images

Supporters of - and protesters against - Donald Trump have been gathering in Windsor ahead of his meeting with the Queen there later.

She will welcome the US president and Melania Trump at the dais in the Quadrangle of Windsor Castle.

Image source, REUTERS/Kevin Coombs

A Guard of Honour, formed of the Coldstream Guards, will give a Royal Salute and the US National Anthem will be played.

The Queen and the president will then inspect the Guard of Honour before watching the military march past. Mr and Mrs Trump will then join the Queen for tea at the castle.

Labour MP Chuka Umunna, who supports the People's Vote campaign for a referendum on the final Brexit deal, said any trade deal done with President Trump would "mean agreeing to his long and unacceptable list of demands".

He said:

Nigel Farage, former Ukip leader and Brexiteer, said he is doubtful that progress has been made on a bilateral trade deal, adding that he thinks we are "almost nowhere".

He told BBC News Channel: "Trump said Mrs May has assured us we can have a trade deal and that's good.

"Frankly he said it with very little sincerity.

"I think he will go back to Washington DC and the administration will be genuinely upset that the UK government has chosen a path of full regulatory alignment."

Some pet owners appear to be getting animals involved.

An ancestral chart mapping Donald Trump's Scottish heritage and a bespoke perfume for the First Lady were the gifts chosen by Theresa May.

Image source, Reuters

Donald Trump has returned to Winfield House, the US ambassador's residence.

He will then head to Windsor Castle where he and his wife Melania will have tea with the Queen.

Meanwhile, crowds are gathering in the town - some to welcome Donald Trump, others to protest his arrival.

Image source, Getty Images