King Charles III is set to arrive in Washington DC on Monday, where he will be hosted by US President Donald Trump

King Charles and Queen Camilla's state visit to the US will go ahead "as planned", Buckingham Palace has said, after a shooting incident in Washington DC raised security concerns.

A statement on Sunday said the decision had been made "after discussions on both sides of the Atlantic through the day".

It is understood there will be minor adjustments to some of the engagements because of security concerns.

They were raised after a gunman attempted to storm the White House Correspondents' Dinner at a Washington hotel on Saturday night. The acting US attorney general says the suspect was likely targeting Donald Trump, who was there.

The palace said the King was "greatly relieved" to hear the US president, Melania Trump and other guests had been unharmed.

It's understood the King and Queen privately reached out to the Trumps to express their sympathies for those caught up in the attack.

The US couple and other senior administration figures were evacuated from the dinner after a man fired several shots while attempting to enter the venue. The suspect, identified in US media as 31-year-old Cole Tomas Allen, was detained at the scene.

There had already been talks about the security around the King and Queen's four-day visit, which begins on Monday, concerning "to what degree the events of Saturday evening may or may not impact on the operational planning for the visit", the Palace had earlier said.

Announcing the visit will now go ahead, the Palace said the King and Queen were "most grateful to all those who have worked at pace" and were "looking forward to the visit getting under way tomorrow".

Acting US Attorney General Todd Blanche said he was "very confident" the King and Queen will be safe during the four-day visit, telling NBC News that Saturday night's incident showed the US security system worked.

Senior government minister Darren Jones told the BBC earlier on Sunday that the King's state visit would have "appropriate security in place in relation to the risk".

Shadow home secretary Chris Philp, meanwhile, said that it was "vital" the King was properly protected, and urged US and UK teams to review the monarch's security overnight.

One Secret Service agent was shot during the incident on Saturday night but was saved by his bullet-proof vest, the president said. No other injures were reported.

Even before that incident, security for the King and Queen's state visit was going to be very tight. Now it will be going up another level.

When Trump visited the UK last autumn, almost all the events happened inside Windsor Castle. He was carried by helicopter in and out of that secure bubble, and so was kept away from any contact with the public.

It is not yet clear what adjustments have been made to the trip. The King had been expected to address both houses of Congress, visit the 9/11 memorial in New York and attend a wreath laying to honour fallen US and UK soldiers in Virginia.

The state visit has already proven diplomatically challenging for those planning it.

It is due to take place days after reports emerged that the US could review its position on UK sovereignty over the Falklands Islands.

Trump has also been highly critical of the UK government and other allies over their response to the Iran war. (BBC)

• King Charles III is set to arrive in Washington DC on Monday, where he will be hosted by US President Donald Trump. Photo credit: BBC| Getty Image