The King is poised to deliver a landmark address to Congress tomorrow, aiming to soothe tensions by highlighting the enduring ability of the UK and the US to find common ground.

In his speech, he is expected to subtly counter President Trump’s recent critical remarks about the UK’s military capabilities, especially the Royal Navy, by alluding to his own distinguished service history.

President Trump, frustrated with British Prime Minister Sir Keir Starmer’s perceived lack of support for his conflict with Iran, recently belittled UK military assets as mere “toys,” claiming, “You don’t even have a navy. You’re too old and have aircraft carriers that don’t work.”

Royal officials note that the King, who leads the British armed forces, will express pride in his naval service and highlight the longstanding alliance between the US and UK, emphasizing that their defense, intelligence, and security cooperation spans decades.

In his address, the King will touch on significant contemporary issues like NATO—which Mr. Trump has threatened to leave—AUKUS, and the situations in the Middle East and Ukraine.

This event marks the King as only the second British monarch to speak before a joint session of Congress, following in the footsteps of his mother, Queen Elizabeth II, who addressed Congress in 1991.

President Donald Trump and first lady Melania Trump greet King Charles III and Queen Camilla as they arrive at the White House today 

Pictured: King Charles III with US President Donald Trump at Windsor Castle on September 18, 2025

King Charles III and Queen Camilla are greeted by US Protocol Chief Monica Crowley (R) as they arrive on day one of their state visit to the United States today 

His 20-minute address is written on the advice of Government to support their strategic priorities, but the language and tone will be his own.

The overall message of the speech will be that while we live in times of great challenge, nationally and internationally, by defending and reaffirming our shared democratic values – values which have been woven deep into the fabric of both our nations throughout history – we can promote security and prosperity now and for the future, not just for our two countries, but for the whole world.

In his opening remarks, Charles will also make brief reference to the events of Saturday evening, in a spirit of solidarity, sympathy and support, as he brings ‘the highest regard and friendship of the British people to the people of the United States’ in this landmark anniversary year.

Turning to the main theme, he will reflect that while the UK and US have not always agreed on all matters over the past 250 years, the foundations of our ‘democratic, legal and social traditions’ – stretching all the way back to the Magna Carta – are such that ‘time and again, our two countries have always found ways to come together’.

When they do so, he will say, the results are not just of national, but global benefit.

In addressing these values, the King will speak of his own faith and his belief that in the hearts of our two nations lies ‘a generosity of spirit and a duty to foster compassion, to promote peace, to deepen mutual understanding and to value people of all faiths and none’.

Such values, he will say, need defending.

He plans to reflect on how defending our common ideals is ‘crucial for liberty and equality’, as is the rule of law which lies at the heart of our democratic traditions and of our shared economic prosperity.

President Donald Trump bids farewell to King Charles III at Windsor Castle during the state visit by the President of the United States on September 18, 2025 

Looking to the future, His Majesty will reference the importance of the trade and technology deals that will play a vital part the continued economic partnership of the two counties.

He will also celebrate America’s many natural wonders, and stress how important it is to defend and protect ‘Nature’s own economy’, too.

How well those comments will sit with President Trump, a notable climate change denier who has ripped up many of his country’s green initiatives, remains to be seen.

However the two men have cordially discussed the issue before.

The King will conclude by noting that the story of our two nations over the last 250 years is one of ‘reconciliation and renewal’, giving rise to ‘one of the greatest alliances in human history’.

It is an alliance which His Majesty hopes and prays will continue to protect and celebrate the values he holds dear, long into the future.

Later in the day the King will give another speech at a glittering state dinner at the White House, where President Trump will also speak.