Trump's victory is a warning sign, says Tusk

“This means that we should finally get our acts together and bring back a sense of direction, bring back confidence, bring back a sense of order.”

The European project is being attacked by populists from across Europe, a trend that had its biggest success with the UK's vote to leave the EU.

Tusk also called on Trump to work together with the European Union.

“I do not believe that any country today can be great in isolation,” said Tusk, referring to Trump's campaign slogan Making America great again.

The Pole, who represents the EU's national governments, gave a statement on Wednesday (9 November) afternoon, without taking any questions.

He said that although US-EU ties are historically strong, the American election result had led to uncertainty over the future of transatlantic relations.

“I listened with attention to president-elect Trump's call for American unity. I, in turn, would like to call for European and transatlantic unity,” said Tusk.

He noted that it will take “major efforts from both sides” to continue to work together.

“The EU is a strong and reliable partner and will remain so. We expect the same from America and its new president.”