WASHINGTON — This city’s biggest party is turning into the must-miss event of the year.

The Trump administration said on Tuesday that the entire White House staff would skip next month’s White House Correspondents dinner as a gesture of solidarity with President Trump, a severe critic of the news media who has already said that he will not attend.

Mr. Trump’s snub will signify the first time since the 1970s that a president has skipped the event, a celebrity-laden fixture of the Washington social calendar that is usually meant to symbolize comity between politicians and the press.

But the absence of the entire White House staff — including the press secretary, Sean M. Spicer, along with cabinet secretaries and powerful advisers — may be unprecedented in the dinner’s history, and it comes with tensions between journalists and the administration at a fever pitch.

In a statement on Tuesday, Mr. Spicer said the decision was fueled by the administration’s displeasure with how Mr. Trump had been treated by the press.