The Trump Administration announced by Presidential Proclamation Thursday it plans to impose tariffs of 25 percent on imported steel and 10 percent on imported aluminum from the European Union (EU), Canada, and Mexico.  The tariffs took effect at midnight Thursday.

After first announcing global steel and aluminum import tariffs in March, the White House delayed implementation for some countries–including the EU, Canada and Mexico–creating an opportunity for trading partners to offer concessions to reduce the overall U.S. trade deficit. The U.S. is now planning to let the EU, Canada and Mexico’s exemptions lapse.

Multiple sources have said the administration’s tariff plans could still change and late negotiations are ongoing, but suggest that changes are unlikely.

The White House has said the tariffs are based “in light of our national security interests,” thus keeping the move within U.S. and WTO law that allows countries to execute trade moves to protect its national security.

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.

In response, the EU said it would “impose duties on a number of imports from the United States,” referring to a 10-page list of targets for retaliation it published in March.  That list included Kentucky bourbon, jeans,  and Harley-Davidson motorcycles.

European leaders have also vowed to proceed with a complaint to the World Trade Organization. “This is protectionism, pure and simple,” said Jean-Claude Juncker, president of the European Commission. They plan to retaliate against the move with as much as $3.3 billion in tariffs on U.S. exports under a rule at the World Trade Organization (WTO) that allows members to retaliate against a country immediately for inappropriately seeking “safeguards” against their exports.

Mexican officials said they will levy import taxes, at an unknown percent, on U.S. exports of pork bellies, apples, cranberries, grapes, certain cheeses, and various types of steel  “Mexico deeply regrets and rejects the decision of the United States to impose these tariffs on imported steel and aluminum from Mexico as of June 1,” Mexico’s economy ministry said in a press release.

Canada levied a surtax on up to $16.6 billion of American steel, aluminum, and other products, according to a Canadian Department of Finance notice published late Thursday.

President Trump has suggested possibly levying tariffs on more products, including EU car and auto-part exports, but no official announcement has been made.