A growing trans-Atlantic rift that was on display over the weekend is appearing more pronounced by the day. On Tuesday, US President Donald Trump ridiculed his French counterpart, Emmanuel Macron, while German Chancellor Angela Merkel called for a European army to confront a changing geopolitical landscape.

Merkel’s renewed calls for such a force, which were an endorsement of Macron’s statements to that effect over the weekend, were met with a mingling of loud applause and boos at a meeting of the European Parliament, German daily Die Welt reported.

“We should work on the vision of one day creating a true European army,” Merkel said in the speech. “A common European army would show the world that there will never be war between the European countries again.”

The words came as Trump mocked Macron, throwing in a swipe about France’s loss in World War II.

As chatter of a deal with China trade is building, Trump reminded his Twitter audience that his trade disputes aren’t limited to disagreements with Beijing. He also continued his campaign to rehabilitate the term nationalism, which he has only recently begun using openly to describe his administration’s policies.

Macron made headlines in a speech over the weekend, during which he called nationalism a “the exact opposite of patriotism.”