European leaders are preparing for a showdown on trade when they meet Donald Trump at the G20 summit in Hamburg next month.

“Whoever believes that the world’s problems can be solved by isolationism and protectionism is mistaken,” Germany’s chancellor, Angela Merkel, told her parliament on Thursday.

French president Emmanuel Macron chimed in: “If free trade is questioned by a member state then we need to address this.”

He added that he hopes “others will see reason” on issues like climate change and terrorism, which require multilateral cooperation.

Europe and the United States account for half the world’s economic output and a third of its trade.

America first

The last time Macron and Merkel met Trump, at the G7 summit in Italy, the American blocked a joint statement reaffirming the top industrialized nations’ commitment to free trade.

He also tried, and failed, to divide the EU by calling for bilateral trade talks. The Europeans have ceded trade authority to Brussels.

Trump ran on a platform of putting “America first”. As president, he has pulled the United States out the Trans Pacific Partnership (TPP) and the Paris climate accord.

He has also hinted at a renegotiation of NAFTA and disparaged NATO allies for supposedly not paying their fair share.

Opposite direction

Europe, traditionally less pro-trade than the United States, is moving in the opposite direction.

Countries this year ratified a free-trade agreement with Canada. The bloc as a whole is negotiating new trade pacts with Japan and Mexico, the third and fifteenth largest economies in the world, respectively, and two nations that have been left in the cold by Trump’s withdrawal from TPP.