In a post on June 20, Paul Waldman wrote: “Who knows what sort of aid Russia and North Korea will give to the Trump campaign, now that he has invited them to offer their assistance?” The word “invited” in the article was hyperlinked to a transcript of an ABC News interview with Mr. Trump, in which he said he would consider accepting information from a foreign government about a political opponent.

The Trump campaign accused The Post of making “false and defamatory” statements.

“There has never been any statement by anyone associated with the campaign or the administration ‘inviting’ Russia or North Korea to assist the campaign in 2019 or beyond,” the court filing said. “There also has never been any reporting that the campaign has ever had any contact with North Korea relating to any United States election.”

A spokeswoman for The Post, Kristine Coratti Kelly, said on Tuesday, “It’s disappointing to see the president’s campaign committee resorting to these types of tactics, and we will vigorously defend this case.”

Theodore J. Boutrous Jr., a lawyer at Gibson Dunn who has previously worked on high-profile media cases, said the lawsuit “flies in the face of basic First Amendment doctrine.”

“The complaint is attacking opinions where the authors are expressing their views based on widely reported facts,” he said. “It’s all part of the overarching war on the press.”