President Joe Biden used humor to go on the attack against 2024 challenger Donald Trump at a Washington dinner Saturday night.

Biden attended the annual Gridiron Club dinner. It is the oldest journalistic organization in the nation's capital.

He joked that two candidates had clinched nominations for president but one was too old and mentally unfit. "The other's me," Biden said.

Biden, 81, also addressed criticism about his memory by highlighting moments when Trump, 77, has slipped up, the Associated Press reported.

"Don't tell him, he thinks he's running against Barack Obama, that's what he said," said Biden.

Biden also made jokes at his own expense, says he was up way past his bedtime.

He even ribbed Florida's Republican Gov. Ron DeSantis over claims that he wears lifts in shoes to appear taller.

"We're committed to helping the little guy... Ron DeSantis, but he won't take our calls," Biden quipped, according to the Daily Mail.

It was the first time Biden had attended the annual dinner during his presidency.

Biden did turn serious, highlighting what he sees as a real threat to democracy should Trump return to the White House.

"We live in an unprecedented moment in democracy," he said. "An unprecedented moment for history. Democracy and freedom are literally under attack. Putin's on the march in Europe. My predecessor bows down to him and says to him, 'Do whatever the hell you want.'"

Biden, dressed in white-tie attire as is the custom, brought his daughter Ashley and sat at the head table along with Vice President Kamala Harris.

Biden stayed after the dinner and mingled with guests and was seen on one X video FaceTiming with the mother of one attendee.

The dinner was held at the Grand Hyatt. No photos or TV cameras were allowed.