A suspected gunman has been charged with attempting to assassinate US President Donald Trump after storming a black-tie dinner.

Cole Tomas Allen, 31, of Torrance, California, wore a blue prison jumpsuit at his first appearance in Washington DC federal court on Monday (local time).

Allen is also accused of shooting a US Secret Service agent as he tried to breach security at the Washington Hilton on Saturday and faces firearms charges.

The accused, who describes himself as a mechanical engineer, game developer and teacher, was arrested after the attack at the White House Correspondents’ Association Dinner, an annual gala for journalists and politicians.

Seated at the defence table flanked by US Marshals, Allen said he would answer all questions truthfully and that he had a master’s degree in computer science.

Prosecutors are seeking his detention while the case moves forward.

Cole Tomas Allen appeared in court in Washington. Photo: AAP

Allen left a manifesto with family members referring to himself ‌as the “friendly federal ‌assassin” and discussing plans to ⁠target senior Trump administration officials who were in the hotel ballroom.

Acting US Attorney General Todd Blanche said his targets ​likely included Trump himself.

White House press secretary Karoline Leavitt on Monday (local time) compared the rhetoric in the manifesto to criticism of Trump by his political opponents.

“Much of the manifesto of the would-be assassin is indistinguishable from the words that we hear daily from so many,” Leavitt said.

“The entire Democrat Party has made their pitch to voters ⁠across the country that Donald Trump poses an existential threat to democracy, that he ‌is a ​fascist.”

Prominent elected Democrats have condemned the shooting.

Melania slams Kimmel

Meanwhile, US first lady Melania Trump has issued a scathing rebuke of late-night TV host Jimmy Kimmel over a joke before the dinner in which he called her an “expectant widow”.

In a rare public attack, Melania called on US broadcaster ABC to “take a stand” against the Jimmy Kimmel Live! star after his monologue.

“Enough is enough. It ‌is time for ABC to take a stand. How many times will ABC’s leadership enable Kimmel’s atrocious behaviour at the expense of our community,” she said in a post on X.

Kimmel, in a parody of the White House Correspondents’ Dinner that aired last week before the actual event, said: “Mrs ‌Trump you have a ‌glow like ⁠an expectant widow.”

“Kimmel’s hateful and violent rhetoric is intended to divide our country,” Melania Trump said.

“His monologue about my family isn’t comedy — his words are corrosive and deepens the political sickness within America.

“People like Kimmel shouldn’t have the opportunity to enter our homes each evening to spread hate.”

Melania Trump was rushed out of the dinner on Saturday with her husband after the shooting in the lobby of the Washington Hilton.

Trump also chimed in on Tuesday (AEST), demanding Kimmel be fired.

“I appreciate that so many people are incensed by Kimmel’s despicable call to violence, and normally would not be responsive to anything that he said but, this is something far beyond the pale,” he posted to Truth Social.

“Jimmy Kimmel should be immediately fired by Disney and ABC.”

In an interview after the attack, Trump said it had been a “traumatic” experience for Melania, who looked stunned when the gunshots were heard in the Hilton lobby.

“I’ve been through this before a couple of times, and she has not — to this extent. She handled it great,” Trump told CBS News’ 60 Minutes.

“I don’t want to say, and people don’t like having it said that they were scared, but certainly, I mean, who wouldn’t be when you have a situation like that?” he said.

In September, the head of the US ⁠Federal Communications Commission pressured broadcasters to take Kimmel off ‌the ​air.

ABC briefly suspended Kimmel’s show that month over his comments about the assassination of conservative ​activist Charlie Kirk.

-with AAP