A California man has been charged with attempting to assassinate US President Donald Trump after trying to storm a gala event with weapons on Saturday night.

Cole Tomas Allen, 31, was also charged with two firearms offences when he appeared in court in Washington DC on Monday. He did not enter a plea.

He was carrying a semi-automatic handgun, a pump-action shotgun and three knives as he charged past a security checkpoint at the White House Correspondents' Association dinner on Saturday, say prosecutors. The incident has sparked a White House security review.

A Secret Service agent was shot but not seriously wounded during the attack at a hotel. The accused faces life in prison if found guilty.

Dressed in a blue jumpsuit with a nametag, the suspect appeared calm at Monday's court appearance in the nation's capital.

He was softly spoken as he answered almost every question from the judge with either "yes, your honour" or "no, your honour".

He stated his age and said he had a master's degree.

Three US marshals stood behind him, and one was at his side, while the federal prosecutor handling the case, US Attorney for Washington Jeanine Pirro, looked on.

During Saturday night's incident, Trump, Vice-President JD Vance, cabinet members and other White House officials were rushed from the Washington Hilton hotel ballroom after gunfire rang out.

The suspect allegedly rushed through a security checkpoint one floor above the basement venue.

"One Secret Service officer was shot in the chest, but was wearing a ballistic vest that worked," Acting Attorney General Todd Blanche told a news conference on Monday.

"This heroic officer who was hit fired five times at Allen, who was not shot but fell to the ground and was promptly arrested."

Blanche said the suspect is believed to have discharged his shotgun at least once.

It is not clear whether the Secret Service agent was shot by the suspect, or was caught in crossfire from other law enforcement. The agent has been released from the hospital.

Attempting to assassinate the president carries a potential life sentence.

The other charges - transportation of a firearm between states to commit a felony and discharging a firearm in a crime of violence - both have maximum sentences of 10 years. The suspect is due to appear in court again on Thursday.

The court heard that the accused crossed multiple state lines in order to try to kill Trump.

The suspect left his home in the city of Torrance in the Los Angeles area on 21 April, travelling by train to Chicago, said officials.

On 24 April, he left Chicago, and arrived in Washington where he checked into the Hilton on the eve of the gala.

The suspect studied at the prestigious California Institute of Technology, and worshipped at the Pasadena United Reformed Church in the Los Angeles area.

Federal campaign finance records show he donated $25 to a Democratic Party political action committee in support of Kamala Harris for president in 2024.

According to an affidavit, the accused sent an email to his family shortly before the attack that said, "Administration officials... are targets, prioritized from highest-ranking to lowest".

"I would still go through most everyone here to get to the targets if it were absolutely necessary," he allegedly added.

He was remanded in custody and prosecutors said more charges could be filed.

The accused has not been co-operating with investigators, law enforcement sources told the BBC's US partner CBS.

As US investigators look into the third alleged assassination attempt against Trump, security officials are reviewing the president's protection protocols.

Many have questioned whether the security perimeter at the Washington Hilton was strong enough, why attendees were not asked to show ID at the event, and why the president, vice-president and others in the line of succession were all gathered in one place.

In Monday's news conference, the acting attorney general maintained that "law enforcement did not fail" in its job to protect the event.

He noted that the gunman was one floor away, "with hundreds of federal agents between him and the President of the United States".

The Washington Hilton, where John Hinckley Jr attempted to assassinate then-President Ronald Reagan 45 years ago, said it had followed security instructions from the Secret Service.

A senior White House official told the BBC that Trump was "standing by" the leadership of the Secret Service.

White House Chief of Staff Susie Wiles will convene a meeting this week to "discuss protocol and practices for major events", the official also said.

Trump has offered assurances that King Charles III will "be very safe" during his four-day state visit to the US, which began on Monday at the White House.