"The European Union has treated the United States very unfairly when it came to trade ... I've had a lot of problems with (the) European Union, and it may morph into something very big ... from a trade standpoint," Trump said.
The president has always complained about other economies taking advantage of Washington by means of "unfair" trade practices. He repeated his stance in Davos, Switzerland, when sitting down with British journalist Piers Morgan for an interview aired on Sunday, Xinhua news agency reported.
As regards the EU market, Trump said: "We cannot get our product in. It's very very tough," adding products from the EU are sold to the United States with "no taxes -- very little taxes."
Trump's "America First" slogan was snubbed by international politicians and business leaders as they gathered in the Swiss ski resort for the annual World Economic Forum.
During the four-day globalist event, which concluded on Friday, European leaders expressed their worry about the rise of populism amid the Trump administration's decision to pull out from international treaties and organizations as well as the perpetual bursts of nationalist rhetoric from the president himself.
In an interview with Swiss national television RTS, French President Emmanuel Macron called on Trump "to be on board with us on multilateralism," according to media reports.
Trump gave Macron a high praise during the interview with Morgan, saying the young French leader is "a great guy."
"He's a great guy ... His wife is fantastic. I like them a lot. You know, we had dinner at the top of the Eiffel Tower, and everything was closed," Trump said.