Jimmy Fallon's beef with President Donald Trump has officially entered the diss track phase after last night's episode of The Tonight Show.

Fallon on Thursday joined the Roots for a brief segment in which he rapped some of Trump's recent Twitter tirades over a beat alongside emcee Tariq Trotter.

"So the FBI's out, looking for collusion," Trotter and Fallon rapped at one point, "while the president tweets 'I had a great meeting with Putin.'"

Fallon and Trotter's rap is the second shot at Trump that The Tonight Show has taken in a week. Previously, Fallon joked that Trump would me starting his own news channel, Trump News Network, which the host said would be "the only network that tells the truth and nothing but the truth, so help me Vlad."

The pair's feud goes back to last month, when the Hollywood Reporter released a podcast interview with Fallon in which he expressed regret over tussling Trump's hair during a 2016 appearance by the then-presidential candidate.

"I'm sorry. I don't want to make anyone angry — I never do and I never will," Fallon said. "It's all in the fun of the show. I made a mistake. I'm sorry if I made anyone mad. And, looking back, I would do it differently."

Trump seized on Fallon's comments on Twitter following the interview's release, writing that Fallon "is now whimpering" over backlash stemming from the incident.

"@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 not done it differently because it is said to have "humanized" me," Trump wrote. "He is taking heat. He called & said 'monster ratings.' Be a man Jimmy!"

Fallon responded to Trump on Twitter with a donation to the Refugee and Immigrant Center for Education and Legal Services, a non-profit that provides free and low-cost legal assistance to immigrant children, in Trump's name. He also addressed Trump in a monologue on The Tonight Show. As Esquire notes, Fallon's move appeared to end the feud at the time.

Now, though, with last night's rap, it appears the late night beef is back on. Trump, however, has not yet responded.