CNN  — 

President Donald Trump compared an unnamed London hospital to a “war zone” on Friday, saying despite tough gun laws in the UK, it has blood all over the floors from victims of knife attacks.

Trump arrived in Belgium for the NATO summit on Tuesday. From Brussels, he’ll head to the UK on Thursday, where he’ll meet Prime Minister Theresa May and Queen Elizabeth before going to Finland on Sunday.

In recent months, the President has bickered with British officials over his tweets and comments, complicating his relationship with one of America’s closest allies.

Here’s a rundown of his past UK comments:

Trump compares hospital to a war zone

In May, during a speech in Dallas defending gun ownership, Trump offered a grim view of London’s knife crime despite tough gun laws in the UK. He also compared an unnamed London hospital to a “war zone.”

“They don’t have guns. They have knives and instead there’s blood all over the floors of this hospital,” Trump said. “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 that. It’s pretty tough.”

It’s unclear what hospital Trump was referring to. But the BBC reported that a trauma surgeon at the Royal London Hospital recently told the network that his fellow doctors have compared it to an Afghan war zone.

London recorded the highest rate of knife crime per capita of any police force in England and Wales in the year ending March 2017. Last year, London had a total of 116 murders, including at least 80 stabbing victims and 10 gunshot victims, police said.

Trump slams location of US Embassy

In April, Trump criticized the new location of the US Embassy in London after it moved from its long-standing Grosvenor Square site in central London to its new home south of the city.

“We had the best site in all of London,” Trump told supporters during a rally in Michigan, before adding that the embassy has now moved to “a lousy location.” Residents of the area did not take kindly to the description and the embassy issued a statement essentially defending itself against the President’s criticisms.

Trump blamed the embassy deal on the Obama and Bush administrations. But the decision to move out of the Grosvenor Square building was taken under the Bush administration in 2008, mainly because the building was proving harder to secure in an age of terrorist threats. Also, the US government did not wholly own it.

Trump was expected to have a state visit to the UK in February to attend the embassy’s opening. But in January, he tweeted that he was canceling his trip.

“I am not a big fan of the Obama administration having sold perhaps the best located and finest embassy in London for “peanuts,” he tweeted at the time. “Bad deal. Wanted me to cut ribbon-NO!”

This week’s stop will be categorized as a “working visit” – without the elaborate trappings such as a horse parade or a state dinner at Buckingham Palace.

Police figures show London had 4,700 incidents of knife injuries between April 2017 and March. The previous year’s number was 4,446.

Trump says UK health system is broke

Months earlier, in February, Trump had gone after the UK’s National Health Service, saying it’s facing financial woes and accusing Democrats of seeking a similar universal health care system for the United States.

“The Democrats are pushing for Universal HealthCare while thousands of people are marching in the UK because their U system is going broke and not working,” he tweeted. “Dems want to greatly raise taxes for really bad and non-personal medical care. No thanks,” Trump tweeted.

Britain’s Health Secretary Jeremy Hunt swiftly fired back.

“NHS may have challenges but I’m proud to be from the country that invented universal coverage – where all get care no matter the size of their bank balance,” Hunt tweeted at the time. Hunt is now the foreign secretary.

NHS funding is one of the most hotly contested topics in British politics. Trump’s comments highlighted a sensitive subject in the UK as it seeks a balance between maintaining universal access to health care with rising costs and demand.

Chicago gun violence

In November last year, Trump caused outrage in Britain by retweeting three videos posted by Jayda Frandsen, the deputy leader of Britain First, a far-right party.

The inflammatory videos showed people purported to be Muslims carrying out assaults and smashing a statue of the Virgin Mary.

London Mayor Sadiq Khan called Britain First “a vile, extremist group that exists solely to sow division and hatred in our country.” He added that the videos make it clear that Trump is not welcome in Britain for an official visit.

A spokesperson for Prime Minister Theresa May said Trump was “wrong” to share the videos. Trump took aim at May in a tweet.

“Theresa May, don’t focus on me, focus on the destructive radical Islamic terrorism that is taking place within the United Kingdom. We are doing just fine!” he wrote.

Trump’s series of spats with the London mayor

Trump has a history of criticizing London, and has had well-documented spats with its mayor.

In June, he slammed Khan in a tweet shortly after a terror attack in London. At the time, Khan said he has more important things to do than respond to Trump’s “ill-informed tweet,” which he described as out-of-context.

The spats continued even after Trump was elected president. In June last year, Trump slammed Khan in a tweet shortly after a terror attack in London.

London Mayor Sadiq Khan has had several spats with President Donald Trump.

Khan told London residents there’ll be an intensified police presence in the wake of the attacks, and there was no cause for alarm.

“At least 7 dead and 48 wounded in terror attack and Mayor of London says there is “no reason to be alarmed!” Trump tweeted.

At the time, Khan said he has more important things to do than respond to Trump’s tweet, which he described as ill-informed and out-of-context. He later said Trump’s state visit to the UK should be called off because his “policies go against everything we stand for.”