The move is certain to trigger retaliation by the E.U. against American products including Kentucky bourbon and Harley-Davidson motorcycles.

President Donald Trump had announced the tariffs in March, but gave several U.S. allies temporary exemptions while they negotiated potential limits on shipments to the United States.

Tariffs of 25 percent on steel and 10 percent on aluminum will take effect at midnight Thursday on imports from the three U.S. trading partners.

Commerce Secretary Wilbur Ross said the president acted on national security grounds, seeing a rising tide of imports as a threat to the domestic metals industry. “Without a strong economy, you can’t have a strong national security,” Ross said.

Officials from the three trading partners – among Washington’s closest allies for decades – have dismissed the idea that their shipments to American customers endanger the United States.

The United States negotiated voluntary export limits with several other friendly nations, including South Korea, Argentina, Australia and Brazil. Ross said that he intends to continue talks with European diplomats and officials from Canada and Mexico, but those are likely to be contentious.

“We continue to be quite willing, indeed eager, to have further discussions with all of these parties,” Ross told reporters, speaking from Paris where he is attending meetings at the Organization for Economic Cooperation and Development.

Thursday’s action also is expected to complicate U.S. efforts to confront China over trade practices that the administration regards as unfair. The E.U. shares many of Washington’s concerns about China’s efforts to acquire advanced technology through compulsory licensing practices, cybertheft and other measures.

But European officials are increasingly irritated by Trump’s aggressive use of obscure provisions in U.S. trade laws against U.S. allies.

“We are deeply disappointed that the US has decided to apply tariffs to steel and aluminium imports from the EU on national security grounds. The UK and other European Union countries are close allies of the US and should be permanently and fully exempted from the American measures on steel and aluminium,” Britain said in a statement. “We will defend the UK’s interests robustly. We continue to work closely with our EU partners and will consider carefully the EU’s proposals in response.”

Ross, meanwhile, said that he still plans to leave for China on Friday for the resumption of trade talks. Earlier this week, there were reports that the talks might be canceled following Trump’s renewed threat to impose import taxes on $50 billion in Chinese products.