The European Union must cope with the “capricious assertiveness” of President Donald Trump’s administration just as it has to deal with the rise of China and Russian aggression, EU President Donald Tusk said.

“Looking at the latest decisions of President Trump, some could even think: ‘With friends like that, who needs enemies?”’ Tusk told reporters on Wednesday before a summit of EU leaders in the Bulgarian capital, Sofia.

The EU’s 28 leaders are due to discuss two challenges that Trump has confronted them with: his decision to pull out of the Iran nuclear deal, and the U.S. threat to impose tariffs on metal imports. While the EU says these are two distinct issues, leaders are likely to lump both together in a wide-ranging discussion over dinner on how to respond to Trump’s provocations.

Tusk’s comments underscore the rift between the trans-Atlantic allies since Trump came to power on a platform of “America First.” Tensions came to a head with the U.S. president’s decision announced last week to pull out of the landmark Iran nuclear accord which the remaining signatories—Russia, China, France, Germany and the U.K., along with the EU—say is working and they will strive to keep in place.

On trade, Tusk said the U.S. move to impose trade penalties on national-security grounds was “absurd,” since the EU is a core American ally and does not represent a threat. “We need to bring reality back into this discussion,” he said.

All the same, the common challenges posed to EU countries by the Trump administration is forcing the bloc closer together, Tusk said.

“Europe should be grateful for President Trump because thanks to him we have got rid of all illusions” that the EU can rely on others for help, Tusk added. “Europe must do everything in its power to protect, in spite of today’s mood, the transatlantic bond. But at the same time we must be prepared for scenarios where we’ll have to act on our own.”