After three years spent trying to deter Russia from destroying Ukraine, European Union leaders grappled on Monday with possible responses to a major ally who appears determined to start a trade war or perhaps even seize part of their territory.

The European Union must remain united and avoid being naive in the face of threats by U.S. President Donald Trump to levy tariffs on its products, Spanish Economy Minister Carlos Cuerpo said on Monday.

European indexes were trading down in opening European trade after U.S. President Donald Trump outlined sweeping tariffs on Mexico, Canada and China, and signalled the European Union will be next. Germany's DAX fell 2.

European Union leaders are grappling with possible responses to a major ally the United States which appears determined to start a trade war or perhaps even seize part of their territory. The leaders met in Brussels on Monday for a defense summit.

The European Union has said it will “respond firmly” if the US imposes tariffs on the bloc in the latest sign of discontent with President Donald Trump’s trade tactics that are reverberating globally.

European leaders are asserting that President Donald Trump’s proposed tariffs against the European Union will force member states to fight back until the United States respects their economic power. White House officials announced earlier this week that a slew of heavy tariffs would be implemented against the EU,

After three years spent trying to deter Russia from destroying Ukraine, European Union leaders grappled on Monday with how to respond to a major ally who appears determined to start a trade war or even seize part of their territory.

Donald Trump is considering plans to impose a 10 per cent tariff on the EU, The Telegraph understands. The move would pour fuel on the blooming global trade war which began on Saturday when the new US president slapped sweeping levies on goods imported from Mexico,