And President Donald Trump has the authority to alter the tariffs or impose quotas or "do anything he wishes at any point" - allowing "potential flexibility" to resolve the issue.
Washington will announce plans to slap tariffs on European Union steel and aluminium imports as early as Thursday morning, sources said, while the United States commerce secretary said any escalation of their trade dispute would depend on the bloc's reaction.
Qualtrough said the federal government is working to remind its US counterparts of this, and said there are contingency plans in place. News reports say that Trump is determined to keep Germany luxury cars out of the U.S.
The prospect of the metals tariffs taking effect on Friday caused mounting frustration in Europe, the single-largest source of United States steel imports. "This is protectionism, pure and simple", Juncker said.
Immediately after the news broke, representatives of Europe's aluminum industry called for a strong reprisal at the WTO. Ross denied this impression and said that there has been transshipment of Chinese steel and aluminum.
Exports: About half of Canada's production is exported, mostly to the U.S.
"Bad news that @POTUS has made a decision to impose taxes on American consumers buying steel and aluminum from our closest allies -Canada, the European Union, and Mexico (with whom we run a trade surplus on steel)", tweeted Sen.
French President Emmanuel Macron, who unsuccessfully lobbied against both Trump's tariffs and USA withdrawal from the Iran nuclear deal during his official state visit to Washington last month, criticized the tariffs in a speech on Wednesday as part of a larger "nationalist retrenchment" reminiscent of Europe in the 1930s.More news: Call of Duty: Black Ops 4 revealed ahead of October release
Before the tariffs were announced, Canadian Foreign Minister Chrystia Freeland said the Canadian government would take steps to protect jobs and industry, calling the U.S. justification "frankly absurd".
It comes a day before an exemption to the planned tariffs is due to expire.
U.S. Commerce Secretary Wilbur Ross attended meetings at the Organization for Economic Cooperation and Development in Paris on Wednesday, and U.S. Trade Representative Robert Lighthizer joins discussions in Paris on Thursday.
In March, Trump imposed a 25% tariff on steel imports and a 10% tariff on aluminium, but granted temporary exemptions to the EU, Canada, Mexico, Brazil, Australia and Argentina. European officials argue that tit-for-tat tariffs will hurt growth on both sides of the Atlantic and Canada said before the announcement that it would respond in kind.
"We are prepared to react in a united and clear way whatever the decision of the (U.S.) president", he said. They are expected to lead to retaliation from European nations.
Ross, meanwhile, said that he still plans to leave for China on Friday for the resumption of trade talks.
Canada was the largest exporter of steel to the United States by value past year, according to data from Wood Mackenzie. Although Germany is the eighth largest source of steel imports for the United States, the USA market amounts to a low single-digit percentage of the overall German steel industry.
Ross said the US would consider the effect of those measures.