US President Donald Trump has hailed the special relationship between his nation and Britain as he paid a gushing tribute to King Charles during his historic second state visit, calling it one of the highest honours of his life.

It was a day of unprecedented pomp for a foreign leader.

Trump and his wife Melania were treated to the full array of British pageantry. Then, the president sang the praises of his nation’s close ally.

Charles and Camilla, and Donald and Melania Trump
King Charles and Queen Camilla treated the US president and first lady to a day of royal pageantry. (AP PHOTO)

“The bond of kinship and identity between America and the United Kingdom is priceless and eternal. It’s irreplaceable and unbreakable,” Trump said in a speech during a lavish banquet at Windsor Castle, family home to British monarchs for almost 1000 years.

Referring to the so-called special relationship between the two nations, Trump said: “Seen from American eyes, the word special does not begin to do it justice.”

Britain rolled out the royal red carpet, giving Trump the largest military ceremonial welcome for a state visit in living memory. 

Trump made little secret of his delight at being not just the first US leader, but the first elected politician to be invited for two state visits.

“This is truly one of the highest honours of my life,” he said.

King Charles
King Charles heralded a ‘new era’ for the nations’ partnership during his speech at the banquet. (AP PHOTO)

British Prime Minister Keir Starmer hopes the trip will aid his government as it seeks to deepen economic ties, secure billions of dollars of investment, ease tariffs and allow him to press the president on Ukraine and Israel.

Companies including Microsoft, Nvidia, Google and OpenAI have already pledged STG31 billion pounds ($A64 billion) in British investments over the next few years, in AI, quantum computing and civil nuclear energy.

Starmer also wants further progress on trade, after Britain secured the first deal with Trump to lower some tariffs, a win that King Charles pointed to in his speech.

“The United Kingdom was your partner in the first trade deal of your administration, Mr President, bringing jobs and growth to both our countries,” the King said.

“And no doubt we can go even further as we build this new era of our partnership.” 

Prince William and Kate
Prince William and Kate also attended the lavish dinner at Windsor Castle. (AP PHOTO)

While there were many Trump supporters in crowds at Windsor in London, several thousand people marched to protest against the state visit.

“I quite simply dislike everything that Trump and his administration represent around the globe,” retiree Bryan Murray said.

Amongst the guests at Wednesday’s banquet was Rupert Murdoch, whose Wall Street Journal publication the president is currently suing in a $US10 billion ($A15 billion) defamation case over an article linking the president with Epstein. 

Rupert Murdoch
On the guests was Rupert Murdoch, whose Wall Street Journal is being sued by Donald Trump. (AP PHOTO)

While the focus will now turn to geopolitics and trade when Starmer hosts Trump at his Chequers country residence, Wednesday was all about ceremony.

Trump and Melania joined Charles, his wife Queen Camilla and other royals and dignitaries for a carriage procession, with the route lined by 1300 British service personnel.

Later, the Trumps viewed historical items from the Royal Collection relating to the US, and then visited St George’s Chapel, the final resting place of Queen Elizabeth, who hosted Trump for his first state visit in 2019, to lay a wreath on her tomb. She died in September 2022.

There was a further military parade and a flypast by Britain’s Red Arrows aerobatics team, but poor weather meant British and US F-35 military jets – a symbol of bilateral defence collaboration – could not join. 

Princess Kate and Donald Trump
Donald Trump praised Kate as ‘beautiful’ and told William he was in line for ‘unbelievable success’. (AP PHOTO)

The Trumps also found time for a private meeting with the King’s elder son Prince William and the heir’s wife Kate, which was described by the prince’s spokesperson as “warm and friendly”. 

Trump later praised “beautiful” Kate and said William was “going to have unbelievable success in the future”.

As for Charles, the 76-year-old monarch, he was a “very, very special man”, the president said.

With AP