Trump thrills in apparent royal ties as he welcomes King Charles to the White House on historic day

US President Donald Trump has joked about his aspirations to live at Buckingham Palace as King Charles and Queen Camilla kick off the second day of their US state visit.

It is a historic day in Washington as the King tries to emphasise a bond between the UK and the US that is so strong it can withstand the political turmoil of the moment.

He and Queen Camilla were formally welcomed by the president and first lady Melania Trump to the White House on Tuesday morning (Wednesday morning AEST) morning with a military ceremony on the South Lawn, ahead of the King's address to Congress on Capitol Hill.

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Ahead of the event, Trump revelled in a report in the British media that suggested a royal link for the president.

After an article in the Daily Mail traced back the US president's Scottish ancestorial roots to claim he's related to the current monarch, Trump suggested he may be able to stay in the home at the heart of the British royal family.

"Wow, that's nice," Trump wrote on Truth Social sharing an image of the article.

"I've always wanted to live in Buckingham Palace!!! I'll talk to the King and Queen about this in a few minutes!!! President DJT"

Today, Charles will become the first British monarch to address the US Congress since his mother, Queen Elizabeth II, in 1991. Her speech highlighted the shared history of both countries and the importance of their democratic values, themes Charles will likely look to reinforce.

Such addresses are an opportunity afforded to only the most prominent world leaders, including Pope Francis, Václav Havel and Winston Churchill.

It will likely mark the most extensive public remarks Charles will deliver during a four-day visit to the US that's intended to celebrate the country's 250th anniversary of independence from Britain.

House Speaker Mike Johnson became the first sitting leader of his chamber to address the UK parliament earlier this year. He attended a garden party with the king in Washington on Monday and said he told him he would be "well received" in Congress.

Under grey, drizzly skies, Trump quipped that it was a "beautiful British day". The king shook hands with members of Trump's Cabinet and joined the president for a rendition of the national anthem.

In his welcome remarks, Trump highlighted the shared history between the two countries and sought to draw a line from King John's sealing of the Magna Carta in 1215 to the American Revolution.

"American patriots today can sing, 'My country, 'tis of thee, sweet land of liberty,' only because our colonial ancestors first sang, 'God save the King,'" Trump said.

The two leaders huddled in the Oval Office for a meeting that was closed to the public, reducing the potential for the freewheeling, sometimes controversial meetings with foreign officials that have become routine during Trump's second term.

Given the expressly apolitical nature of the British monarch and Trump's fondness for the royal family, the likelihood of an awkward meeting was likely reduced anyway.

Afterward, Trump said it was a "really good meeting" and Charles is a "fantastic person".

While the gentlemen met, the ladies attend a cross-cultural educational event at the White House Tennis Pavilion.

Trump will host the royal couple on Tuesday evening for a state banquet at the White House.

The visit comes at a challenging moment for US-UK relations. Trump's up-and-down relationship with British Prime Minister Keir Starmer has taken a particularly sour turn over the past several months as the Republican president has sought to rally international support for the war in Iran.

Trump criticised Starmer, who has largely resisted his overtures, by saying "this is not Winston Churchill that we're dealing with".

Trump has also imposed tariffs on the UK and warned of additional levies despite a Supreme Court ruling earlier this year that has made such unilateral moves more challenging.

Trump threatened just last week to slap a "big tariff" on the UK if it doesn't scrap a digital services tax on US technology companies.

Meanwhile, Charles has faced some calls on Capitol Hill to meet with victims of Jeffrey Epstein while he is in the US.

There's no indication that he will do so even as the scandal involving the convicted sex offender has ensnared his brother, who was arrested in February over misconduct allegations, which he denies.

Charles and Camilla arrived at the nation's capital on Monday and held a tea with the president and first lady Melania Trump. The royal couple will continue their US trip later this week with stops in New York City and Virginia.

- Reported with Associated Press.

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