Donald Tusk
Donald TuskReuters

European Council President Donald Tusk called US President Donald Trump an 'existential threat' to Europe Tuesday.

Tusk wrote an open letter to the leaders of 27 Council member states, in which he listed the US President as a "threat" to the European Union alongside China, Russia, radical Islam, war, and terrorism.

Tusk cited "worrying declarations by the new American administration" as the basis for his including President Trump with other threats to the EU. He said that the threats "make our future highly unpredictable.”

“Particularly the change in Washington puts the European Union in a difficult situation; with the new administration seeming to put into question the last 70 years of American foreign policy,” Tusk said.

He added that the breaking up of the EU would result in its member states becoming subservient to non-European powers. “The disintegration of the European Union will not lead to the restoration of some mythical, full sovereignty of its member states, but to their real and factual dependence on the great superpowers: the United States, Russia, and China.”

Many European leaders have condemned President Trump's executive order banning nationals of seven countries from entering to the US.