He said: "The UK loves me, in fact my mother was from the UK, they love me there even if they are not treating us well with trades, but they will".
Ignoring all diplomatic niceties, the convention-shredding United States president set up the four-day visit with a rebuke of his beleaguered host as she battles to stop her government falling apart over Brexit.
"I've always liked writing amusing songs and he just lends himself to them".
Asked about Trump's comments at a hastily-arranged meeting with journalists, May said she was delivering wishes of the British people. But I would like to see them work out Brexit quickly.
"I would say Brexit is Brexit, the people wanted to break it up so I would imagine this is what they will do".
"There is no stronger alliance than that of our special relationship with the U.S. and there will be no alliance more important in the years ahead", the British leader said.
The president was delayed for nearly an hour when the North Atlantic Treaty Organisation summit in Brussels he had been attending overran because he demanded member states increase their contributions faster than originally planned.
As well as in London, protests are expected to take place in Bristol, Newcastle, Leeds, Cambridge and Cardiff after Trump arrives on Thursday.
Trump added that the U.K.is a "pretty hot spot", given the recent upheaval in the government there. After the visit, Trump will decamp to Finland for a one-on-one with Russian President Vladimir Putin on July 16.
Tens of thousands of people are expected to attend more than 100 protests being held across the country against the American President's visit over the weekend.
The US president's brash style and hardline "America First" policies have caused consternation across Britain's political spectrum and society.
The prime minister will host a gala dinner and a meeting with Trump, giving them time to talk.
Mr Trump will instead be ensconced at Windsor Castle, west of London on Friday when a blimp tethered next to the Houses of Parliament.
They are scheduled to spend Thursday night at the US Ambassador's home Winfield House, which is in Regent's Park.
Rarely has a foreign leader been so mocked on an official visit - London's mayor, Sadiq Khan, a Muslim who has challenged Trump's worldview OK'd the balloon, which is an apt symbol of Trump's tempestuous relationship with Britain, traditionally the United States' closest ally.
He is also expected to visit Scotland - where he owns two golf courses - before heading back to the US.