President Donald Trump will turn from pageantry to policy Tuesday as he joins British Prime Minister Theresa May for a day of talks likely to highlight fresh uncertainty in the allies’ storied relationship.

Trump and May are due to meet with corporate executives from the United States and United Kingdom, before an afternoon news conference on the second day of Trump’s state visit. The leaders’ top priority is a possible bilateral trade deal to take effect once the U.K. leaves the European Union.

“Big Trade Deal is possible once U.K. gets rid of the shackles. Already starting to talk,” Trump tweeted Monday, as he launched his visit with a day of royal pomp and circumstance. He and first lady Melania Trump paid a visit to Buckingham Palace, where Queen Elizabeth II greeted them with a smile. The evening ended with a lavish state dinner.

President Donald Trump walks with Prince Charles and first lady Melania Trump walks with Camilla, the Duchess of Cornwall, after arriving at Buckingham Palace, Monday, June 3, 2019, in London. (AP Photo/Alex Brandon)
President Donald Trump walks with Prince Charles and first lady Melania Trump walks with Camilla, the Duchess of Cornwall, after arriving at Buckingham Palace, Monday, June 3, 2019, in London. (AP Photo/Alex Brandon)

Britain is scheduled to leave the EU on Oct. 31 unless both sides agree to an extension. Its position is in flux because May is stepping down as party leader Friday, setting in motion a race to succeed her as prime minister.

It is traditional for U.S. and other world leaders not weigh in on another’s domestic politics. But Trump hasn’t let that stop him. Trump told the Sunday Times in an interview that Britain should “walk away” from talks and refuse to pay a 39 billion-pound ($49 billion) divorce bill if it doesn’t get better terms from the EU.

The president also says Brexit party leader Nigel Farage, an outspoken advocate of leaving the EU without a deal, should be given a role in the negotiations.

Britain's Queen Elizabeth II greets President Donald Trump as he arrives for a welcome ceremony in the garden of Buckingham Palace, in London, Monday, June 3, 2019, on the first day of a three day state visit to Britain. (Victoria Jones/Pool via AP)
Britain’s Queen Elizabeth II greets President Donald Trump as he arrives for a welcome ceremony in the garden of Buckingham Palace, in London, Monday, June 3, 2019, on the first day of a three day state visit to Britain. (Victoria Jones/Pool via AP)

Trump has also taken the unusual step of saying that Conservative Party leadership candidate Boris Johnson would make an “excellent” leader for the U.K.

The meeting with business leaders at St. James’ Palace will bring together 10 leading companies — five from the UK and five from the United States. They’ll explore where cooperation could benefit both sides.

CEOs and senior representatives from BAE Systems, GlaxoSmithKline, National Grid, Barclays, Reckitt Benckiser, JP Morgan, Lockheed Martin, Goldman Sachs International, Bechtel and Splunk are expected to attend.

Britain's Queen Elizabeth II greets President Donald Trump, center, and first lady Melania Trump, left, with Britain's Prince Charles and Camilla, Duchess of Cornwall during a ceremonial welcome in the garden of Buckingham Palace in London, Monday, June 3, 2019 on the opening day of a three day state visit to Britain. (AP Photo/Frank Augstein)
Britain’s Queen Elizabeth II greets President Donald Trump, center, and first lady Melania Trump, left, with Britain’s Prince Charles and Camilla, Duchess of Cornwall during a ceremonial welcome in the garden of Buckingham Palace in London, Monday, June 3, 2019 on the opening day of a three day state visit to Britain. (AP Photo/Frank Augstein)

As often happens when Trump travels overseas, norms were shattered, including when the president complained about his television viewing options in the foreign capital and urged people to punish CNN by boycotting its parent company, AT&T.

Following Tuesday’s focus on business and trade, Trump will use the next two days to mark the 75th anniversary of the June 6, 1944, D-Day landing, likely the last significant commemoration most veterans of the battle will see. The events will begin in Portsmouth, England, where the invasion was launched, and then move across the Channel to France, where Allied forces began to recapture Western Europe from the Nazis.

___

President Donald Trump stands with Queen Elizabeth II, with first lady Melania Trump, left, and Prince Charles and Camilla, the Duchess of Cornwall, right, at Buckingham Palace, Monday, June 3, 2019, in London. (AP Photo/Alex Brandon)
President Donald Trump stands with Queen Elizabeth II, with first lady Melania Trump, left, and Prince Charles and Camilla, the Duchess of Cornwall, right, at Buckingham Palace, Monday, June 3, 2019, in London. (AP Photo/Alex Brandon)
Britain's Queen Elizabeth II waits to greet President Donald Trump and first lady Melania Trump as they walk up the steps with Britain's Prince Charles, right, and Camilla, Duchess of Cornwall, left, during a ceremonial welcome in the garden of Buckingham Palace in London, Monday, June 3, 2019 on the opening day of a three day state visit to Britain. (AP Photo/Frank Augstein)
Britain’s Queen Elizabeth II waits to greet President Donald Trump and first lady Melania Trump as they walk up the steps with Britain’s Prince Charles, right, and Camilla, Duchess of Cornwall, left, during a ceremonial welcome in the garden of Buckingham Palace in London, Monday, June 3, 2019 on the opening day of a three day state visit to Britain. (AP Photo/Frank Augstein)
Marine One, with President Donald Trump aboard, arrives at Buckingham Palace, Monday, June 3, 2019, in London. (AP Photo/Alex Brandon)
Marine One, with President Donald Trump aboard, arrives at Buckingham Palace, Monday, June 3, 2019, in London. (AP Photo/Alex Brandon)
FILE - In this July 13, 2018, file photo, Britain's Queen Elizabeth II and President Donald Trump inspect the Guard of Honour, at Windsor Castle, in Windsor, England. Like a bull who keeps going back to the china shop, Trump is returning to Europe.  (Ben Stansall/Pool Photo via AP)
FILE – In this July 13, 2018, file photo, Britain’s Queen Elizabeth II and President Donald Trump inspect the Guard of Honour, at Windsor Castle, in Windsor, England. Like a bull who keeps going back to the china shop, Trump is returning to Europe. (Ben Stansall/Pool Photo via AP)
In this May 31, 2019, photo, workers build a fence around Winfield House, ahead of the State Visit by President Donald Trump, in London. Like a bull who keeps going back to the china shop, Trump is returning to Europe.  (AP Photo/Frank Augstein)
In this May 31, 2019, photo, workers build a fence around Winfield House, ahead of the State Visit by President Donald Trump, in London. Like a bull who keeps going back to the china shop, Trump is returning to Europe. (AP Photo/Frank Augstein)
President Donald Trump salutes an honor guard as he and first lady Melania Trump arrive at Stansted Airport in England, Monday, June 3, 2019 at the start of a three day state visit to Britain. (AP Photo/Kirsty Wigglesworth)
President Donald Trump salutes an honor guard as he and first lady Melania Trump arrive at Stansted Airport in England, Monday, June 3, 2019 at the start of a three day state visit to Britain. (AP Photo/Kirsty Wigglesworth)
The visitors books signed by US President Donald Trump and his wife Melania after their tour of Westminster Abbey in central London, Monday, June 3, 2019. Trump is on a three-day state visit to Britain. (Stefan Rousseau/Pool Photo via AP)
The visitors books signed by US President Donald Trump and his wife Melania after their tour of Westminster Abbey in central London, Monday, June 3, 2019. Trump is on a three-day state visit to Britain. (Stefan Rousseau/Pool Photo via AP)
US President Donald Trump, left,  is greeted by Britain's Prince Charles and Camilla, the Duchess of Cornwall prior to afternoon tea at Clarence House, in London, Monday, June 3, 2019. Trump is on a three-day state visit to Britain. (Victoria Jones/Pool Photo via AP)
US President Donald Trump, left, is greeted by Britain’s Prince Charles and Camilla, the Duchess of Cornwall prior to afternoon tea at Clarence House, in London, Monday, June 3, 2019. Trump is on a three-day state visit to Britain. (Victoria Jones/Pool Photo via AP)
President Donald Trump and first lady Melania Trump are having afternoon tea with Prince Charles and his wife, Camilla, at their official residence in central London. (June 3)
President Donald Trump and first lady Melania Trump are having afternoon tea with Prince Charles and his wife, Camilla, at their official residence in central London. (June 3)
President Donald Trump on Monday laid a wreath at the Grave of the Unknown Warrior in London's Westminster Abbey. (June 3)
President Donald Trump on Monday laid a wreath at the Grave of the Unknown Warrior in London’s Westminster Abbey. (June 3)
US President Donald Trump and his wife Melania were greeted Monday on the grand lawn of Buckingham Palace by Queen Elizabeth II with a Guard of Honor formed by the Grenadier Guards wearing the traditional bearskin hats. (June 3)
US President Donald Trump and his wife Melania were greeted Monday on the grand lawn of Buckingham Palace by Queen Elizabeth II with a Guard of Honor formed by the Grenadier Guards wearing the traditional bearskin hats. (June 3)
U.S. President Donald Trump has arrived in the U.K. on the first leg of a trip that will include commemorating the 75th anniversary of D-Day during a ceremony at the Normandy American Cemetery in France. (June 3)
U.S. President Donald Trump has arrived in the U.K. on the first leg of a trip that will include commemorating the 75th anniversary of D-Day during a ceremony at the Normandy American Cemetery in France. (June 3)
President Donald Trump is set to begin a state visit to the United Kingdom on Monday. He said he plans to meet with politicians who support Britain's exit from the European Union, and that there is an opportunity for a U.S.-British trade deal. (June 3)
President Donald Trump is set to begin a state visit to the United Kingdom on Monday. He said he plans to meet with politicians who support Britain’s exit from the European Union, and that there is an opportunity for a U.S.-British trade deal. (June 3)