The Queen appeared to issue a coded caution over Donald Trump’s readiness to disrupt institutions like the UN on the first day of a state visit which began with a lavish royal welcome.

At a state banquet she hosted for the president in the Buckingham Palace ballroom, the monarch spoke of the “close and long-standing friendship” between the two allies.

However, in proposing a toast to her guest, she added: “After the shared sacrifices of the Second World War, Britain and the United States worked with other allies to build an assembly of international institutions to ensure that the horrors of conflict would never be repeated.

“While the world has changed, we are forever mindful of the original purpose of these structures – nations working together to safeguard a hard-won peace.”

The President hailed the monarch as “a great, great woman” and praised the UK’s role in the “mighty endeavour of righteous nations” of D-Day, whose 75th anniversary he will mark with Ms May later this week.

President Trump in Britain for state visit: In pictures Show all 40 1 /40 President Trump in Britain for state visit: In pictures President Trump in Britain for state visit: In pictures President Trump, Prime Minister Theresa May and Jeremy Hunt, the foreign secretary, pose for a photo during dinner at Winfield House, the US ambassador's residence in London AFP/Getty President Trump in Britain for state visit: In pictures President Trump and Prime Minister Theresa May share a laugh outside of Downing Street Reuters President Trump in Britain for state visit: In pictures President Trump walks with the Queen while other guests follow as they arrive at a state banquet in Buckingham Palace AFP/Getty President Trump in Britain for state visit: In pictures The red carpet is rolled out in front of Downing Street prior to the arrival of President Trump AP President Trump in Britain for state visit: In pictures President Trump meets with prime minister Theresa May for a business roundtable meeting at St James' Palace in London AP President Trump in Britain for state visit: In pictures President Trump makes a speech at the state banquet in Buckingham Palace Getty President Trump in Britain for state visit: In pictures President Trump and the Queen share a toast at the state banquet in Buckingham Palace Reuters President Trump in Britain for state visit: In pictures Philip May and Melania Trump attend a garden party for families of Downing Street staff on the second day of President Trump's visit Getty President Trump in Britain for state visit: In pictures President Trump meets with the Queen at Buckingham Palace as he arrives on the first day of his three-day state visit PA President Trump in Britain for state visit: In pictures A mixed crowd of supporters and detractors waits outside Buckingham Palace ahead of the arrival of President Trump Reuters President Trump in Britain for state visit: In pictures President Trump and the Queen view an exhibition of items from the Royal Collection that are of historical significance to the US PA President Trump in Britain for state visit: In pictures President Trump inspects an honour guard during a welcome ceremony in the garden of Buckingham Palace AP President Trump in Britain for state visit: In pictures The police block a road leading to Westminster Abbey, where Donald Trump is visiting on the first day of his state visit PA President Trump in Britain for state visit: In pictures President Trump walks with Prince Charles in the gardens of Buckingham Palace AFP/Getty President Trump in Britain for state visit: In pictures The McDonalds restaurant on Whitehall near to Westminster Abbey provides an excuse as to why they are not serving milkshakes today, though many have speculated that it is due to the recent trend of pouring milkshakes over right wing political figures Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures Protesters with anti-Trump signs stand on Whitehall near Downing Street Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures President Trump and First Lady Melania are welcomed by the Queen, Prince Charles and Camilla at Buckingham Palace EPA President Trump in Britain for state visit: In pictures King's Troop Royal Horse Artillery perform a gun salute to honour President Trump's state visit and to mark the 66th anniversary of Queen Elizabeth's coronation at Green Park Getty President Trump in Britain for state visit: In pictures A protester stands on Whitehall near Downing Street holding a sign with an anti-Trump message Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A supporter welcomes the president's visit on Whitehall near Downing Street Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A miniature Trump balloon in the protest on Whitehall near Downing Street Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A protester wears a "No Trumps" card in his hat as he walks nearby to Buckingham Palace Getty President Trump in Britain for state visit: In pictures President Trump walks with Prince Charles and a Buckingham Palace guard as he is welcomed on the first day of his three-day state visit AFP/Getty President Trump in Britain for state visit: In pictures Dedicated pro-Trump and pro-Brexit campaigner Joseph Afrane awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures Crowds watch as Marine One, the helicopter carrying President Trump, arrives at Buckingham Palace PA President Trump in Britain for state visit: In pictures President Trump and First Lady Melania depart from Air Force one at Stansted Airport Reuters President Trump in Britain for state visit: In pictures Supporters of the president - and detractors of London mayor Sadiq Khan - await his arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures President Donald Trump salutes an honour guard as he and first lady Melania Trump arrive at Stansted Airport AP President Trump in Britain for state visit: In pictures President Trump and First Lady Melania arrive at Winfield House, the US ambassadors residence in London AP President Trump in Britain for state visit: In pictures An anti-Trump protester awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures Dedicated pro-Trump and pro-Brexit campaigner Joseph Afrane awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A protester mowed this message into a field nearby to Stansted Airport Born Eco President Trump in Britain for state visit: In pictures An anti-Trump protester awaits the president's arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures A marching band parades down the Mall in front of Buckingham Palace ahead of the arrival of President Trump Reuters President Trump in Britain for state visit: In pictures Supporters of the president await his arrival at Buckingham Palace Tom Batchelor / The Independent President Trump in Britain for state visit: In pictures President Trump shakes hands with Jeremy Hunt, the foreign secretary Sky News President Trump in Britain for state visit: In pictures A policeman stands on the Mall, one of the roads leading to Buckingham Palace that is closed for the president's visit Reuters President Trump in Britain for state visit: In pictures Air Force One lands carrying U.S. President Donald Trump and First Lady Melania Trump arriving for their state visit to Britain Reuters President Trump in Britain for state visit: In pictures An honour guard await Trump's departure from Air Force One at Stansted Airport Sky News President Trump in Britain for state visit: In pictures President Trump and First Lady Melania depart from Air Force one at Stansted Airport AP

While he steered largely clear of politics, Mr Trump appeared to signal his support for Brexit by saying that he wanted to “affirm the common values that will unite us long into the future – freedom, sovereignty, self-determination”.

And in a tweet issued shortly after his comments, the White House said: “President Trump supports Brexit being accomplished in a way that maintains global economic stability while securing voters’ wishes for UK independence.”

Mr Trump and wife Melania were treated to the full pomp and ceremony of a state visit, as they were greeted by the Queen in Buckingham Palace and shown parts of the sovereign’s art collection before laying a wreath at the Grave of the Unknown Warrior in Westminster Abbey and dining on fillet of halibut and Windsor lamb saddle at the banquet.

In a break in proceedings, the president found time to tweet: “London part of trip is going really well. The Queen and the entire Royal family have been fantastic. The relationship with the United Kingdom is very strong.”

He said there had been “tremendous crowds of well-wishers”, adding: “Haven’t seen any protests yet, but I’m sure the Fake News will be working hard to find them. Great love all around.”

The president is on Tuesday expected to press Theresa May to block Chinese tech giant Huawei out of the UK’s 5G telecoms network in discussions in Downing Street talks on the second day of a state visit which began on Monday with a lavish royal welcome.

In an apparent sign of the waning influence of the outgoing prime minister, there will be no one-on-one talks between the president and Ms May, who will stand down as Conservative leader at the end of the week.

Discussions in 10 Downing Street are expected to focus on the prospects for a post-Brexit trade deal, but points of tension will include Mr Trump’s decision to pull the US out of the Iran nuclear deal and the Paris Agreement on action to stop climate change, as well as his pressure on Western allies to close sensitive communications networks to Huawei, which Washington suspects of opening the door to spying by China’s communist regime.

The Queen shows Donald Trump and Melania the items and artworks from the Royal Collection

Thousands of protesters are expected to gather on Tuesday for a rally in Trafalgar Square featuring speakers including Labour leader Jeremy Corbyn and PCS union boss Mark Serwotka, who will say Trump is “not welcome here in Britain”.

Trade is high on the agenda for talks between the president and Ms May, who will co-host a meeting of British and American business leaders in St James’s Palace ahead of their summit.

In an indication of the UK’s hopes for closer commercial ties after Brexit, Ms May will tell the meeting: “It is a great partnership, but one I believe we can make greater still.

“With a bilateral free trade agreement, with broader economic co-operation, and by continuing to work together to underpin, shape and influence the global economy and its rules and institutions – keeping markets free, fair and open, and keeping our industries competitive.”

Mr Trump once more held out the prospect of boosted trans-Atlantic trade after Brexit, saying: “Big Trade Deal is possible once UK gets rid of the shackles. Already starting to talk!”

But a survey by the IPPR thinktank found that US priorities for a free trade deal conflict with UK voters’ preferences in areas including food safety, climate change and state aid, with only 8% saying they would accept a US agreement if it meant lowering food standards, against 82% who would not.

IPPR senior research fellow Marley Morris said: “On Sunday US Ambassador Woody Johnson said of US food that ‘if the British people like it, they can buy it’. It seems from our poll findings that a resounding majority of the British people would choose to pass up Ambassador Johnson’s offer.”

The president is expected to use the Downing Street meeting to repeat his call for Britain to seek “alternatives” to Huawei in developing its next-generation telecoms network.

A series of contenders to replace Ms May as PM, including foreign secretary Jeremy Hunt and home secretary Sajid Javid, have indicated they are ready to overturn her reported decision to allow the Chinese company to bid for “non-core” parts of the 5G programme.

And Conservative MP Bob Seely, a member of the Commons Foreign Affairs Committee who last month co-authored a Henry Jackson Society report which found Huawei posed a possible security risk, said: “It’s quite clear what Theresa May should do. She should tell the president that her successor will review the issue. There is a very strong case for building hi-tech from China out of our system, not into it. It is not just a technical issue, it’s a moral and ethical one – China has an appalling record of hacking and abuse of data both for espionage and spying on its own people.”

Downing Street sought to play down the significance of the fact that May and Trump will meet with their delegations of ministers and officials, and not one-on-one, insisting there was “nothing unusual” about the set-up.