Mr Romney – formerly a Republican Party nominee for the 2012 US election – heaped praise on the incoming President after the pair had dinner together at one of the hotels Trump owns in New York.
Applauding Trump’s message, which Mr Romney said promotes “inclusion”, he added that he had a “wonderful evening” with the billionaire hotelier.
Mr Romney’s highly optimistic praise of Trump is in stark contrasts to comments he made during the US election, when he slammed the reality TV star as a “phoney” and a “fraud”.
Businessman Mr Romney previously blasted Mr Trump – claiming “dishonesty is Donald Trump”s hallmark” and accusing him of bullying, greed, misogyny and “absurd third grade theatrics”.
Mr Romney added: “Here”s what I know: Donald Trump is a phoney, a fraud.
“His promises are as worthless as a degree from Trump University.
“He”s playing members of the American public for suckers. He gets a free ride to the White House, and all we get is a lousy hat.”
Despite Mr Romney’s harsh words, Trump has met with the ex-Republican leader twice since winning the US election in order to discuss him the Cabinet.
But critics have insisted Mr Romney must apologise to Trump.
Chris Collins, the first member of congress to back Trump in his Presidential campaign, said there was “no question” over whether Mr Romney ought to say sorry.
He said: “You know Mitt Romney said some awful things but now we are seeing chief executive Donald J. Trump who’s going to run our country like a business, surround himself to the best and brightest.