US President Donald Trump has lashed out at Jimmy Fallon, telling him to "be a man" and saying he too regrets his 2016 interview with the late night TV host.
Mr Trump tweeted his dissatisfaction with the interview on Sunday night (US time), saying Fallon is now "whimpering to all that he did the famous 'hair show' with me (where he seriously messed up my hair)."
"And that he would have now done it differently because it is said to have 'humanised' me - he is taking heat. He called and said 'monster ratings!' Be a man Jimmy!" the post reads.
Mr Trump was referring in his tweet to a 2016 interview on Fallon's show in which he tussled the former real estate mogul's hair.
People saw the move as Fallon "humanising" Mr Trump, rather than interviewing him about the issues raised in his presidential campaign.
The pair's interview followed the public outcry Mr Trump was facing during the election, particularly after an Access Hollywood tape leaked of Mr Trump telling Billy Bush he would grab women "by the p***y" in a 2005 recording.
Fallon last year publicly apologised for the interview, telling The Hollywood Reporter he "made a mistake" by treating him as he did on the show.
The host responded to the US President's tweet with a snide reference to Mr Trump's US-Mexico border control policies.
"In honour of the President's tweet I'll be making a donation to RAICES in his name," referring to the non-profit organisation that offers education and legal services to refugees in Texas.