BRUSSELS (CN) — While some celebrated openly, most European leaders put on a brave face for President Donald Trump’s return to the White House, stressing the need for good transatlantic ties — but subtly, some warned they would defend Europe’s economic interests.

U.S. President Donald Trump has promised to address a longstanding trade deficit with the European Union, saying he will reverse that by imposing tariffs or making the EU buy more U.S. oil and gas.

EU, German and Chinese leaders took turns defending global cooperation in Davos on Tuesday as the spectre of new trade wars looms following Donald Trump's return to the White House.

The European Commission has rejected US President Donald Trump's claims that the United States runs a trade deficit of $350 billion with the European Union. A commission spokesman said the $350-billion deficit does not exist and that the US and the EU have complementary strengths.

Donald Trump has headed straight to actions. Right from his first minutes in the White House, he cut the Gordian knot and implemented a major change of course in U.S. economic policy. Not only is he threatening to charge Mexico and Canada a 25% tariff on their products exported to the U.