President-elect Donald Trump | Drew Angerer/Getty Images Donald Trump: I’ll start off trusting Putin President-elect says he plans to strengthen travel restrictions on Europeans visiting the US.

U.S. President-elect Donald Trump will invite British Prime Minister Theresa May to visit him "right after" his inauguration and will strike a "fair" trade agreement with the U.K. "very quickly," he told the Times in an interview published Sunday.

Brexit "is going to end up being a great thing” and other countries will follow the U.K.'s lead out of the EU, largely as a result of the migration crisis, Trump said.

The interview will boost campaigners pushing May to agree to a hard Brexit with Britain outside the European single market and will worry many among the Continent's Establishment. Trump's desire to strike a deal with President Vladimir Putin is likely to be welcomed by Russia but his comments will provoke concern in Ukraine, Poland and the Baltic countries.

“I do believe this, if they [EU countries] hadn’t been forced to take in all of the refugees, so many, with all the ­problems that it ... entails, I think that you wouldn’t have a Brexit," Trump said. "It probably could have worked out but this was the final straw, this was the final straw that broke the camel’s back ... I believe others will leave.”

The interview, the first extensive comments to European press since Trump became president-elect, was conducted by Michael Gove, a columnist for the Times and former U.K. justice secretary, and Kai Diekmann, publisher and former editor of Bild newspaper. Gove, who worked for the Times before being elected to the U.K. parliament, was a prominent Brexit campaigner during Britain’s referendum in June and was sacked by May after he failed in a bid to become prime minister following the Brexit vote.

Trump said that while he had "great respect" for Germany's Chancellor Angela Merkel, "she made one very catastrophic mistake and that was taking all of these illegals, you know, taking all of the people from wherever they come from."

He added that the EU was pandering to Germany, at others' expense.

“You look at the European Union and it’s Germany. Basically a vehicle for Germany. That’s why I thought the U.K. was so smart in getting out.”

While Russia's actions in Syria were "a very bad thing" and had led to a “terrible ­humanitarian situation," the U.S. president-elect said he intended to start his presidency trusting Putin and Merkel.

“Well, I start off trusting both — but let’s see how long that lasts. It may not last long at all,” he said.

Trump, who will be inaugurated Friday, said he hoped to strike a deal with Russia to reduce its nuclear capability in exchange for sanctions relief.

“They have sanctions on Russia — let’s see if we can make some good deals with Russia. For one thing, I think nuclear weapons should be way down and reduced very substantially, that’s part of it.”

Trump has previously said it might not be bad if countries such as South Korea, Japan and Saudi Arabia developed nuclear weapons for self defense.

On NATO, Trump said he was committed to the alliance, but added that the U.S. paid more than its fair share and the organization had not adapted to today's threats.

“I said a long time ago that NATO had problems. No. 1 it was obsolete, because it was designed many, many years ago. No. 2 the countries aren’t paying what they’re supposed to pay. I took such heat, when I said NATO was obsolete. It’s obsolete because it wasn’t taking care of terror... With that being said, NATO is very important to me."

The incoming president also said he planned to sign orders next Monday to strengthen U.S. border control, which would include travel restrictions on Europeans visiting the country and "extreme vetting" of those entering the U.S. from parts of the world known for Islamic terrorism.

Trump said he intended to appoint his son-in-law Jared Kushner to forge a Middle East peace deal, and called on the U.K. to veto any U.N. Security Council resolutions critical of Israel.