WASHINGTON, July 19 (Xinhua) -- U.S. President Donald Trump on Thursday attacked the European Union (EU), saying Europe's latest fining of U.S. tech-giant Google showed that the bloc "truly" has "taken advantage of the U.S."

"The European Union just slapped a Five Billion Dollar fine on one of our great companies, Google," Trump tweeted. "They truly have taken advantage of the U.S., but not for long!"

"I told you so!" he added, referring to his earlier harsh remarks toward Brussels over trade deficit and defense spending sharing.

The European Commission said on Wednesday that it is set to fine Google 4.3 billion euros (around 5 billion U.S. dollars) for monopoly with its Android operating system, accusing it of violating the EU competition rules.

Google CEO Sundar Pichai later challenged the antitrust fine and vowed to appeal the case.

Trump's remarks came before the scheduled visit of European Commission President Jean-Claude Juncker on July 25. The White House said Trump and Juncker will focus on improving transatlantic trade and forging a stronger economic partnership.

Trump's top economic adviser Larry Kudlow said on Wednesday that he expected Juncker to come with a "significant" free trade offer.

However, Juncker, for his part, told a news conference on the same day that the European Union would not be intimidated on trade, and "we will continue to react tit-for-tat to the provocations that might be thrown at us."

He added that he would seek to explain to Trump that since the European Commission coordinates trade policy for the European Union, Washington could not forge a trade deal with just one of its members.

The United States on Monday filed five disputes at the WTO against five trading partners, including the EU, for announcing trade tariffs in retaliation to its own on aluminum and steel imports.