U.S. President Donald Trump waves as he boards Air Force One to depart for Vietnam | Pool photo by Kevin Dietsch via Getty Images Trump to EU: Play ball or ‘we’re going to tariff the hell out of you’ US president says EU is ‘maybe, in certain ways’ tougher than China.

U.S. President Donald Trump on Monday issued a renewed threat to Brussels that the EU has to "play ball" in trade talks or "we're going to tariff the hell out of you."

"The European Union is very, very tough. Very, very tough. They don’t allow our products in. They don’t allow our farming goods in," Trump said at a meeting with U.S. governors, according to a transcript from the White House. He added that "maybe, in certain ways," the EU is "tougher than China."

Trump also accused the EU of charging "big tariffs" on American cars, "whereas we charge them almost nothing when they send their cars to us."

The EU's tariff on cars is 10 percent, while the U.S. tariff is at 2.5 percent. Brussels wants to negotiate lowering auto tariffs with Washington as part of a planned trade deal, but it has been the U.S. side that has so far rejected talks on this issue.

Washington is, however, pushing the EU to include agriculture in talks, which Brussels refuses. Trump has until mid-May to decide whether to impose tariffs, potentially set at 25 percent, on auto imports in the name of national security, which the EU fears will be used as leverage in negotiations.

"We’re taking care of it," Trump said, adding: "I mean, we’ve informed them that, 'Look, if you don’t — if you’re not going play ball …'”

Though he did not initially complete this sentence, he added later: "They have to meet. And we told them, 'Have to meet. Sorry. And if you don’t meet, we’re going to tariff the hell out of you.' And they’re going to meet."