U.S. President Donald Trump has promised to address a longstanding trade deficit with the European Union, saying he will reverse that by imposing tariffs or making the EU buy more U.S. oil and gas.

U.S. duties could nudge the European Union toward protectionist measures and away from free trade.

Business leaders in Davos joined calls by U.S. President Donald Trump for the European Union to speed up efforts to reduce regulation and increase competition to prevent the bloc from falling further behind other developed markets.

"The European Union is very, very bad to us," he told reporters. "So they're going to be in for tariffs. It's the only way…you're going to get fairness," he added. Trump's ire stems from trade deficits with European countries,