US President Donald Trump on Monday held off on imposing controversial tariffs on steel and aluminum from the European Union, Canada and Mexico, offering them a 30-day reprieve after fears of a trade war spooked Wall Street.

The 25 percent tariffs on steel and 10 percent duties on aluminum were set to go into effect on Tuesday, as temporary exemptions granted in March to the EU, Canada, Mexico and other US allies expired.

Europe had lined up its own punitive tariffs on American imports, including iconic items such as Harley-Davidson motorbikes, blue jeans and bourbon whiskey — but for now, instead, negotiations will continue.

The Trump administration is “extending negotiations with Canada, Mexico and the European Union for a final 30 days, the White House said in a statement.

In formal proclamations, Trump said the “necessary and appropriate means to address the threat to the national security” posed by the metal imports is to “continue these discussions and to extend the temporary exemption of these countries.”

The US also announced it had finalized a trade deal with South Korea, which includes several concessions made by Seoul, including extended tariffs on pick-up trucks and a quota on its steel exports.

Washington has “agreements in principle” with Argentina, Australia and Brazil, “the details of which will be finalized shortly,” the statement said.

“In all of these negotiations, the administration is focused on quotas that will restrain imports, prevent transshipment, and protect the national security.”

The Trump administration has told trading partners they must make concessions, but the EU has insisted it will not negotiate without first obtaining a permanent exemption.