The European Union must remain united to respond to U.S. President Donald Trump's threats to levy tariffs on its products, Spanish Economy Minister Carlos Cuerpo said on Monday.

The EU was open to trade and in favour of a globalised world market, though the bloc should not be "naive" and protect its companies and should make sure they were in a position to compete in equal conditions with rivals from other countries, Cuerpo said in an interview with Spanish radio station RNE.

Newly elected Trump ordered sweeping tariffs on goods from Mexico, Canada and China on Saturday.

In the past Trump has vowed imposing tariffs on European goods too, though White House press secretary Karoline Leavitt said on Friday he has not made up his mind about a timeline for implementing those tariffs.