Trump tells gun rally that knife crime made London a 'war zone'

US President Donald Trump advocated gun ownership by criticising Britain and France where he claimed terrorist attacks and stabbings could have been prevented if citizens were armed.

Speaking at the Dallas rally of the National Rifle Association (NRA) on Friday, Trump said that due to "unbelievably tough gun laws", the UK has a knife problem with a top hospital in the capital having "blood all over the floors".

"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," he said.

"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, knives," the president added, while pretending to stab someone.

"London hasn't been used to that. They're getting used to it. It's pretty tough."

On France, he said the shooting attacks in Paris could have been "a whole different story" if guns were turned on the attackers. While mimicking a gunman, he said terrorists "took their time" and gunned people down "one by one". 

The NRA campaigns to protect the US Second Amendment giving Americans the right to bear arms.

Trump's speech comes three months after one of the world's deadliest school shootings when 17 people were killed in Parkland, Florida. The massacre fuelled public demand for change to gun laws.

The US leader is scheduled to make a "working visit" to the UK on July 13, though mass protests have been planned against his trip.

He cancelled a previous visit to open the new US embassy in London because he did not like the location and cost of the building. 

Agencies contributed to this report.