France, April 29 -- Donald Trump promised Tuesday that he is just getting started as he marked the radical and vengeful beginning of a presidency that has shaken the world and destabilised the United States.

Basking in the adulation of cheering supporters in Michigan, the 78-year-old touted the "most successful first 100 days of any administration in the history of our country," even as polls show Americans becoming disenchanted with the economic and political tumult.

Trump said he missed the campaign trail, and launched with visible relish into a speech that often sounded more like that of a candidate than a head of state.

Joe Biden is "sleepy", the media is "fake", judges who oppose him are "communist", Democratic opponents are "radi...