The state visit by Britain's King Charles III to the US would take place as planned, Buckingham Palace said on Sunday, following a shooting at a Washington media gala.

The incident late Saturday at the annual dinner of the White House Correspondents' Association came less than 48 hours before Charles and Queen Camilla begin a four-day state visit to the United States.

The palace said that Charles was "greatly relieved" that Trump, his wife Melania and other guests were unharmed and later on Sunday said the trip would go on as planned.

"The King and Queen are most grateful to all those who have worked at pace to ensure this remains the case and are looking forward to the Visit getting underway tomorrow," it said.

Earlier, senior UK minister Darren Jones told British broadcasters during a round of interviews that security teams in Britain and the US were "working closely to ensure the security arrangements are put appropriately in place" for the state visit.

It is understood the king and queen reached out privately to the Trumps to express their sympathies with those impacted Saturday night, and to share their gratitude to the security services who prevented further injury.

Trump has said one law enforcement officer was shot at close range but appeared not to be critically injured.

During the four-day state visit -- organised to honour the historic relationship between Britain and the US as America marks 250 years of independence -- Charles and Camilla will visit Washington and New York.

Charles will become the first British monarch to address Congress since his mother, the late queen Elizabeth II, in 1991, while the royal couple will have tea with Trump and Melania and attend a state dinner.

- Tensions -

It comes as transatlantic tensions over the Iran war and the Epstein scandal's long shadow threaten to intrude on the landmark visit.

Trump has repeatedly lambasted British Prime Minister Keir Starmer over his war opposition, as well as his government's immigration and energy policies.

The pair spoke by phone Sunday, when Starmer "extended his best wishes... following the shocking scenes at last night's White House Correspondents Dinner", Downing Street said.

"He expressed his relief that the President and First Lady were safe and wished a speedy recovery to the officer injured," it added.

They also discussed "the urgent need to get shipping moving again in the Strait of Hormuz, given the severe consequences for the global economy and cost of living for people in the UK and globally," Starmer's office noted.