Germany's new economy minister will travel to Washington Sunday for talks with US officials, his office said, after President Donald Trump's plans to slap hefty tariffs on steel and aluminium raised fears of a global trade war.

Peter Altmaier, a close ally of Chancellor Angela Merkel, will discuss "tariffs, steel and trade" with US government representatives, a ministry spokeswoman said.

The visit, scheduled to last until Tuesday, comes after Trump stunned trading partners earlier this month when he suddenly pledged to impose 25-percent duties on imported steel and 10 percent on aluminium.

Trump says the shock measures are in response to "unfair" trade practices, but countries around the world have vowed to retaliate, raising the spectre of a tit-for-tat trade war.

The European Union has so far pushed back the hardest, drawing up a list of US products -- including peanuts and motorcycles -- it could hit with countermeasures.

Trump has repeatedly singled out Germany for criticism, complaining about America's massive trade deficit with Europe's biggest economy and threatening to tax German car imports.

Merkel has called for dialogue and warned that "no one can win in such a race to the bottom".

The chancellor told German public broadcaster ARD on Wednesday she believed the EU should speak as one voice in the trade row.

"The best response first of all is a united stance by the members of the European Union," she said.

But at the same time, Brussels "should not be afraid to take measures if it becomes necessary, even if we don't want to."

Trump's metals levies are due to take effect on March 23, but he has signalled that some countries could be exempted.

EU Trade Commissioner Cecilia Malmstroem is set to meet with US Commerce Secretary Wilbur Ross next week in a bid to defuse the r