European Union chief Donald Tusk (Photo: AFP/VNA)

His comments came as Trump, in France for World War I centenary commemorations, blasted French President Emmanuel Macron over his proposals for a European army.

The EU Council president has previously voiced fears that Trump was seeking to tear down the post World War II order, with the US leader once calling the EU a foe in trade.

Looking ahead to the European Parliament elections in May, Tusk warned against the emergency of a nationalist front opposed to the EU itself. The former Polish prime minister also spoke of rising anti-European sentiment in several capitals, saying some forces wanted "conflict rather than cooperation, disintegration rather than integration".