"I know it is politically not necessarily correct to say that, but I will say it and I will say it loud," Trump said during a joint press conference with British Prime Minister Theresa May.
“I think it's been very bad for Europe. I think Europe is a place I know very well and I think what has happened is very tough. It's a very tough situation,” Trump said. “I just think it's changing the culture. It's a very negative thing for Europe.”
“The UK has a proud history of welcoming people who are fleeing persecution to our country,” she said. “We have a proud history of welcoming people who want to come to our country to contribute to our economy and society.”
"Over the years, overall immigration has been good for the UK," she continued. "It brought people with different backgrounds and outlooks here to the UK and we've seen them contributing to our society and economy."
She went on: “What is important is that we have control of our borders and we have a set of rules that enable us to determine who comes into our country, and of course that is what, as a government, we have been doing for a number of years and will continue to do in the future.”
During the press conference, the president lashed out at immigration laws back home, too.
"We have very bad immigration laws," Trump said about American immigration policy. "We're doing very well considering the fact that we don't have immigration laws."
“I think allowing millions and millions of people to come into Europe is very, very sad,” Trump said in the interview.
He went on: “I think what has happened to Europe is a shame.”
“I think it changed the fabric of Europe and, unless you act very quickly, it’s never going to be what it was and I don’t mean that in a positive way,” Trump said.
“I think you are losing your culture. Look around. You go through certain areas that didn’t exist ten or 15 years ago,” he continued.
Trump linked the immigration to European countries to terrorism and crime, and pointed a finger to London’s mayor Sadiq Khan as part of the problem.
“Take a look at the terrorism that is taking place. Look at what is going on in London. I think he has done a very bad job on terrorism," Trump said.
“I think he has done a bad job on crime, if you look, all of the horrible things going on there, with all of the crime that is being brought in," he went on.
Khan responded to Trump’s claims in an interview Friday with the television show "Good Morning Britain."
“The wonderful thing about our city is the diversity. I hope you’ll realize it’s a strength not to be afraid of, but to be cherished,” Khan said in a pointed rebuke aimed at Trump.
In a separate interview with BBC radio on Friday, Khan called Trump's claims "preposterous."
“The idea that you can blame this on immigration from Africa is I think preposterous and we should call him out when he does so,” Khan said.
While Trump has never explicitly said immigration is a threat to white Americans, he's made numerous disparaging remarks about immigrants who come to the U.S. whether legally or illegally.
Earlier this year, Trump was reported to have derided protections for immigrants from Haiti, El Salvador, and African countries.
"Why are we having all these people from s---hole countries come here?" Trump was reported to have said during an Oval Office meeting with members of Congress.
Critics say Trump's recent language on immigration during his overseas trip mirrors white nationalist rhetoric.
"There's no other way to put it. Trump's comments that immigration is "changing the culture" in US & Europe were ignorant, dangerous, and most of all racist. Are you really okay with this open white supremacy, @GOP?" Rep. Judy Chu, D-Calif., tweeted on Friday.
Trump’s comments while abroad highlight his hardline immigration rhetoric that he often uses on the campaign trail, often linking it to increased crime, citing the gang MS-13. Back in the U.S., Trump’s crackdown on illegal immigration led to a “zero tolerance” policy which drew national outcry after thousands of young migrant children were separated from their families at the southern border.
Trump also brought a similar immigration message to the NATO summit in Brussels.
"I will say that immigration is a very important thing, and I told them today, the EU – the European Union – better be very careful, because immigration is taking over Europe, and they better be very, very careful. And I said that loud and clear."