Late-night host Jimmy Fallon used his opening monologue Monday on NBC’s “The Tonight Show” to address Twitter attacks against him by President Donald Trump.

Trump tweeted that Fallon should “be a man” and “stop whimpering” after Fallon expressed regret in an interview about ruffling the then-candidate’s hair on a Sept. 15, 2016, episode.

.@jimmyfallon is now whimpering to all that he did the famous “hair show” with me (where he seriously messed up my hair), & that he would have now done it differently because it is said to have “humanized” me-he is taking heat. He called & said “monster ratings.” Be a man Jimmy! — Donald J. Trump (@realDonaldTrump) 25 June 2018

“As you may have heard last night, the president of the United States went after me on Twitter," Fallon said in his monologue. "So, Melania, if you’re watching: I don’t think your anti-bullying campaign is working.”

“When I saw Trump had insulted me on Twitter, I was going to tweet back immediately, but then I thought I had more important things to do.”

"Then I thought: 'Wait, shouldn't he have more important things to do? He's the president! What are you doing? Why are you tweeting at me?’”

Fallon then joked that being the subject of the president’s Twitter fury was “the only thing I have in common with NFL players.”

The host said his response to the tweet was to make a donation to the Refugee and Immigrant Center for Education and Legal Services (Raices) in Trump’s name. Raices is a nonprofit group that provides legal services to immigrants in Texas.

In honor of the President’s tweet I’ll be making a donation to RAICES in his name. — jimmy fallon (@jimmyfallon) 25 June 2018

“When Trump heard that, he was like: ‘I love Raices, they’re my favorite peanut butter cup. There’s no wrong way to eat a Raices,” Fallon quipped.