French President Francois Hollande said Friday that U.S. President Donald Trump’s administration poses “challenges” for Europe as he and German Chancellor Angela Merkel underscored the need for European unity in the face of growing internal and external threats.

“Let’s speak very frankly, there are challenges, there are the challenges the U.S. administration poses to our trade rules, as well as to our ability to resolve conflicts around the world,” Hollande said in Berlin.

“So we of course have to talk to Donald Trump since he was chosen by the Americans to be their president,” he said at a joint press conference with Merkel.

“But we also have to do so with a European conviction and the promotion of our interests and our values.”

Merkel, without mentioning Trump by name, said: “We see that global conditions are changing dramatically and quickly.”

“And we must respond to these new challenges, both in terms of defending a free society and defending free trade, as well as in terms of the economic challenges.”

“We can only master (these challenges) by working together,” Merkel told the news conference.

She added: “We need a clear, common commitment to the European Union, to what we have accomplished, and to the values of our liberal, democratic democracies.”

The two leaders did not take questions.

Trump has unsettled his traditional European allies with a range of radical policy plans, from calling NATO “obsolete” to announcing he would rip up a planned transatlantic trade plan.

The billionaire president is due Friday to meet British Prime Minister Theresa May, who is set to lead her country out of the EU after last year’s Brexit vote, in his first official meeting with a foreign leader.