Speaking to Good Morning Britain, the President said NHS hospitals were “a sea of blood” because of knife murders - which are at their highest level in England and Wales since records began - in the capital.
He told Piers Morgan: "In London you have stabbings all over.
"I read an article where everybody is being stabbed.
"They said your hospital is a sea of blood, all over the floors.”
The comments were first made by Trump at a public event in Texas last year, when he described a London hospital as “a war zone for horrible stabbing wounds”.
He said at the time: "I recently read a story that in London, which has unbelievably tough gun laws, a once very prestigious hospital, right in the middle, is like a war zone for horrible stabbing wounds.
Read more from Yahoo News UK:
"Yes, that’s right, they don’t have guns, they have knives. And instead there’s blood all over the floors of this hospital. They say it’s as bad as a military war zone hospital.
"Knives, knives, knives."
Trump used the interview to also backtrack on comments he made about the NHS being part of a post-Brexit trade deal.
Following a backlash from Tory leadership candidates, Labour and trade unions, Trump softened his stance.
He told GMB: "I don't see it being on the table. Somebody asked me a question today and I say everything is up for negotiation, because everything is.
"But I don't see that as being, that something that I would not consider part of trade. That's not trade.”
Trump has arrived in Portsmouth on the final day of his state visit to the UK for a national commemoration ceremony, 75 years after the D-Day landings before heading to Ireland.