Major US trading partners announced countermeasures Wednesday after Donald Trump's blanket tariffs on steel and aluminium imports took effect, prompting the president to vow a further response.
The steep 25-percent levies contained no exemptions despite countries' efforts to avert them, marking an expansion from Trump's recent duties on Canada, Mexico and China since returning to the White House.
The European Union swiftly unveiled counter tariffs hitting some $28 billion of US goods in stages from April, while Canada announced additional levies on $20.7 billion of American products from Thursday.
China vowed "all necessary measures" in response, as Washington edged toward an all-out trade war with allies and competitors alike.
European Commission chief Ursula von der Leyen maintained that the retaliation, affecting products ranging from bourbon to motorbikes, is "strong but proportionate."
Trump told reporters Wednesday that Washington would "of course" respond to the countermeasures.
He claimed his country would "win that financial battle" with the EU.
- 'Significant costs' -
Canada, which is heavily exposed to the US steel and aluminium levies, said its own tariffs will hit steel products, aluminium, and goods ranging from computers to sports equipment.
Incoming prime minister Mark Carney later added that he was ready to negotiate with Trump on a renewed trade accord.
His country supplied about half of US aluminum imports and 20 percent of its steel imports, according to a recent note by EY chief economist Gregory Daco.
Besides Canada, Brazil and Mexico are also key US suppliers of steel, while the United Arab Emirates and South Korea are among providers of aluminum.
The Alliance for American Manufacturing said it supported the tariffs and their inclusion of steel derivatives: "This addition will ensure that importers can't game the system."
But the American Automotive Policy Council (AAPC) representing the "Big Three" automakers -- Ford, General Motors and Stellantis -- said it was reviewing the levies.
The group's president Matt Blunt warned that tariffs, including their extension to auto parts with steel and aluminum, "will add significant costs for automakers, suppliers and consumers"
- 'Enough war' -
US Trade Representative Jamieson Greer criticized the EU's promises of retaliation, calling the bloc's economic policies "out of step with reality."
"The EU's punitive action completely disregards the national security imperatives of the United States –- and indeed international security," Greer said.
His remark came after EU Council chief Antonio Costa called on Washington to de-escalate the situation and enter dialogue.
"I think we have enough war in the world, we need to stop the wars we have and not create a trade war," Costa said.
German Chancellor Olaf Scholz, head of Europe's largest and heavily export-oriented economy, condemned Washington's moves as "wrong" and warned of increased inflation.
Beijing's foreign ministry said "there are no winners in trade wars."
China is the world's leading steel manufacturer, although not a major exporter of the product to the United States.
Trump's steel and aluminum tariffs will likely balloon costs of producing goods from home appliances to automobiles and cans used for drinks, threatening to raise consumer prices down the road, experts say.
- 'Massive uncertainty' -
Uncertainty over Trump's trade plans and worries that they could trigger a recession have roiled financial markets. But US stocks regained some ground Wednesday even as some Asia markets retreated.
The threat of protectionism, said Cato Institute research fellow Clark Packard, has allowed US steel and aluminum firms to raise prices: "It's creating massive amounts of uncertainty."
Trump also targeted both metals in his first presidency.
The president has promised further "reciprocal tariffs" from April 2 to tackle what he considers unfair behavior.
The lack of exemptions Wednesday came despite efforts to push for exclusions.
Tokyo expressed regret it had not succeeded while Canberra called the tariffs unjustified.
Canberra and London stopped short of retaliation. The Mexican government said it would not immediately strike back and Brazil said it would not react.
South Korea warning
South Korea expects "unfair trade practices" to become more common, necessitating firm action, a minister said Thursday after Seoul was hit by US President Donald Trump's worldwide tariffs on steel and aluminium.
The steep 25 percent US levies on the metals came into place on Wednesday with no exemptions despite Seoul's efforts to avert them.
Last year, South Korea shipped $3.2 billion worth of steel to the United States, ranking sixth overall, according to data from the International Trade Administration of the US Department of Commerce.
Its $600 million of aluminium exports placed the country fourth among the US suppliers.
"Unfair trade practices are expected to become more frequent, and the government will respond firmly," Trade, Industry and Energy Minister Ahn Duk-geun said at a meeting with major steel companies.
"We are working to strengthen trade defence mechanisms, including monitoring circumvention dumping and steel imports," he added.
Ahn also urged companies to divert their strategies, telling them: "Given the high level of uncertainty, I ask that you consider forward-looking investment and export strategies centered on high-value-added products.
"The government will also focus its support in this direction."
South Korea's trade ministry said a strategy for "addressing unfair steel imports and trade issues" would be developed and finalised in March.
Seoul's other trade minister headed to Washington on Thursday, saying he would "negotiate to minimise economic sanctions" on the country.
The plan was to emphasise "that South Korea is one of the most aligned partners with the United States' economic security policies", Cheong In-kyo told reporters Thursday before he left.
Trump last week criticised South Korea, among other countries, for what he called "unfair" practices, saying Seoul's "average tariff is four times higher" than that of US import taxes.
He also complained that Washington had given "so much help militarily" to South Korea, referring to the tens of thousands of US soldiers stationed there partly to protect against the nuclear-armed North.
Hours after Trump spoke, South Korea's trade ministry issued a statement headlined: "The tariff rate on imports from the United States to South Korea is effectively close to 0 percent" due to a bilateral free-trade agreement.
US exports to South Korea amounted to $65.5 billion in 2024, up 0.7 percent from the previous year, according to Washington, while imports totalled $131.5 billion, a rise of 13.3 percent.
Cars and automobile parts make up nearly a third of South Korea's exports to the United States, while petroleum and metals are its largest imports from the country.