A key message from the UK government will be to encourage the United States to maintain its commitment to Nato and to support Ukraine and there will be a much bigger than usual military line-up for the state visit.

There will be 1,300 service men and women, from the Army, Royal Navy and RAF taking part in the welcome, creating the largest ever guard of honour for a state visit to the UK.

A joint US and UK flypast by F-35 jets and the Red Arrows will fly over Windsor, watched by Sir Keir Starmer alongside the president, in a display showing the closeness of the military relationship.

The centrepiece of the state visit will be the spectacular banquet in St George's Hall, where King Charles and President Trump will make speeches, with guests enjoying a menu that's likely to be a culinary representation of the special relationship, with UK and US food.

Along with the royal pageantry and photo-opportunities, there will be efforts to influence the US president over trade and international co-operation.

State visits are a form of soft power diplomacy, using the royal charm offensive to build relations with important international partners - with none more important than the US.

As the visit got underway, a major technology deal was announced with US tech firms investing £31bn in the UK, including £22bn from Microsoft.

This will see co-operation in artificial intelligence, quantum computing and nuclear power, in a tech deal which Sir Keir Starmer hopes will begin "creating highly skilled jobs, putting more money in people's pockets".

Ahead of the visit, the owner of Google, Alphabet, announced a £5bn ($6.8bn) investment in the UK's artificial intelligence research.

And an agreement is to be signed between the US and UK on accelerating the development of nuclear power.

But ambitions to remove the current 25% tariff on UK steel exports to the US seem to have been put on hold - although this remains lower than the 50% tariff facing many other countries.

President Trump is in UK for historic second state visit