Donald Trump defended US gun laws on Friday night by saying that London was "like a war zone" because of knife crime.

Addressing the annual convention of the National Rifle Association in Dallas, Texas, the US president said: "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.

"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... London hasn't been used to that, they're getting used to it, pretty tough."

Mr Trump did not specify which London hospital he was referring to but one possibility was Barts in east London.

On April 5 an article on the Breitbart website, which Mr Trump is known to read, described Barts as being like a "war zone".

It was based on comments to the BBC Radio 4 Today programme by Dr Martin Griffiths, lead surgeon at Barts Health NHS Trust, making a comparison to Camp Bastion in Afghanistan.

He told the Today programme: "Some of my military colleagues have described their practice here as similar to being at Bastion."