Just a year ago, they might have seemed the oddest of couples. But now President-elect Donald J. Trump and Julian Assange, the WikiLeaks founder, have formed a united front against the conclusion of American intelligence agencies that Russian intelligence used hacked emails to interfere in the presidential election.

Mr. Assange, long reviled by many Republicans as an anarchist lawbreaker out to damage the United States, has won new respect from conservatives who appreciated his site’s release of Democratic emails widely perceived to have hurt Hillary Clinton’s campaign. And Mr. Trump has been eager to undercut the conclusion of the F.B.I., the C.I.A. and other agencies that those emails were provided to WikiLeaks courtesy of Russian government hackers.

In a lengthy interview with Sean Hannity of Fox News that aired on Tuesday night, Mr. Assange repeated earlier denials that WikiLeaks had received the hacked emails from Russian intelligence.

“Our source is not the Russian government,” Mr. Assange said. “And it is not a state party.”

Mr. Trump picked up on Mr. Assange’s claim on Twitter on Wednesday morning, referring to the main targets of the hacking, the Democratic National Committee and Mrs. Clinton’s campaign chairman, John D. Podesta: “Julian Assange said ‘a 14-year-old could have hacked Podesta’ — why was DNC so careless? Also said Russians did not give him the info!”