Donald Trump tells Jimmy Fallon to 'be a man'

Jimmy Fallon is opening up about the personal anguish he felt following the backlash to his now-infamous hair mussing appearance with Donald Trump. Photo / AP

Donald Trump has slammed chat show host Jimmy Fallon over the infamous "hair messing" incident during the 2016 presidential campaign.

In a scathing tweet, the US President told Fallon to stop "whimpering" and "be a man".

The Tonight Show host recently told an interviewer he regretted playfully tousling Trump's hair in the episode as he didn't mean to "normalise [Trump] or to say I believe in his political beliefs".

Trump said Fallon was "taking heat" over the incident as he had privately called him, lauding the episode's "monster ratings".

.@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) June 25, 2018

Hours after the US President's damning tweet, Fallon responded, saying "In honour of the President's tweet I'll be making a donation to RAICES in his name." RAICES Texas is a non-profit firm that provides legal services to immigrants.

The hair-messing TV appearance caused an outcry at the time, with critics accusing Fallon of "humanising" a person who encouraged hateful rhetoric.

Fallon has previously been criticised for not being as political as other US late-night talk show hosts, who regularly use their platforms to take on Trump.