LONDON — Stock markets declined broadly in Europe and Asia on Friday, following a sharp drop in the United States, after President Trump rattled financial markets by saying he would impose strict tariffs on steel and aluminum imports.
The Nikkei 225 fell 2.5 percent in Japan on Friday, and the Hang Seng Index in Hong Kong closed down 1.5 percent.
Major indicies in Europe also were down broadly, with the CAC 40 in France and the Xetra Dax 30 in Germany declining about 2 percent in early trading. The Stoxx Europe 600 index saw nearly every sector in negative territory on Friday morning.
At a meeting with industry executives on Thursday, Mr. Trump said he would formally sign rules enacting tariffs of 25 percent on steel and 10 percent on aluminum next week, surprising some of his closest advisers, who had urged him to not pursue such measures.
The proposed measures angered many of the United States’ closest allies and neighbors.
Jean-Claude Juncker, the president of the European Commission, said on Thursday night, shortly after the comments by Mr. Trump, that the tariffs appear to represent “a blatant intervention” to protect the United States steel industry. He vowed the bloc would not “sit idly while our industry is hit with unfair measures that put thousands of European jobs at risk.”
Canada accounted for the largest share of steel imports into the United States, about 16 percent in 2017, according to the latest data from the United States Department of Commerce’s International Trade Administration. Brazil, South Korea and Mexico are the next biggest exporters to the United States, according to the Commerce Department.
“Any tariff measures that include steel or aluminum from Ontario could have serious negative impacts on workers and businesses on both sides of the border” Kathleen Wynne, the premier of Ontario, the most populated province in Canada, said on Thursday.
Hans Jürgen Kerkhoff, the president of the German Steel Federation, said the proposed tariffs “clearly infringes” on World Trade Organization rules and urged the European Union to take action.
In Europe, Germany accounted for about 4 percent of United States steel imports last year, followed by the Netherlands, with 2 percent; and Italy, with 1.4 percent, according to United States data. Britain accounted for about 1 percent of steel imports last year, and France had less than 1 percent.
Seth Carpenter, a UBS economist, said there was a potential risk to European steel production, as some of the current steel imports to the United States could be directed to Europe.
“The E.U. is the market with least over-capacities and still comparably open for steel volumes, in our view, Mr. Carpenter said in a research note on Friday. “The consequences for the E.U. steel mills could range from lower margins to protective measures fueling steel inflation.”
Steel makers based outside the United States were generally trading lower on Friday after the trade announcement.
Shares of ArcelorMittal, which is based in Luxembourg and is one of the world’s largest steel producers, fell more than 4 percent in Paris on Friday.
The British steel maker Tata Steel also saw its shares drop 4 percent in London on Friday, while the German steel maker ThyssenKrupp declined 3 percent.
The South Korean steel maker Posco was down 3.6 percent on Friday.
Shares of Maanshan Iron & Steel declined 2.6 percent in Hong Kong on Friday, while Angang Steel Company ended the day down 2 percent.
Baoshan Iron & Steel Company, based in Shanghai, saw its shares drop 4 percent on Friday, while the Chinese aluminum maker Yunnan Aluminium Company was down 1.3 percent.
Jeremy Lawson, chief economist at Aberdeen Standard Investments, said the market might be waking up to strains of protectionism that had been emerging as part of the Trump administration’s policies.
“Up until now, most of the market behavior over the past 12 to 15 months has been a reaction to macro economic environment, the big sort of tax policy changes,” Mr. Lawson said. “The creeping protectionist that we are sort of seeing in the announcements around Canada lumber, solar panels, washing machines, the Section 232 investigation that proceeded this announcement, the intellectual property investigation around China — these types of things don’t really appear to have affected markets up until now. “
The market may also be factoring in potential retaliation in terms of trade by the European Union and China as a result of the Trump administration’s actions, he said.