The U.S. is looking with fresh eyes at Europe's antitrust rules, according to the EU's competition commissioner.

At a press conference at the Web Summit in Lisbon, Portugal, on Wednesday, Margrethe Vestager said the U.S. has a "renewed deeper interest and curiosity as to what we are doing in Europe" on antitrust and tech regulation.

Her response followed President Donald Trump's comments earlier this week that his administration is looking into antitrust violations by Amazon, Facebook and Google parent company Alphabet.

"We have a very close working relationship with the DOJ (Department of Justice) and the FTC (Federal Trade Commission) on mergers and of course we also discuss cases when we come together," Vestager said in response to a question from CNBC.

"I find that not only with this president but also with other presidents there is a very strong partnership across the Atlantic when it comes to these matters."

Trump has previously attacked the European Union for levying antitrust fines against U.S.-headquartered companies like Google. Vestager said the U.S. and the EU recognize their differences in matters like legislation but said there is growing interest on both sides of the political aisle in the U.S. when it comes to competition enforcement.