President Biden on Wednesday called for major increases in some tariffs on steel and aluminum products from China, speaking to members of a national steelworkers union in Pittsburgh as he competes with former President Donald J. Trump for votes in northern industrial states. .

“These are strategic, targeted actions that will protect American workers and ensure fair competition,” Biden told a crowd of about 100 members of the United Steelworkers union, which endorsed him last month. “Meanwhile, my predecessor and MAGA Republicans want blanket tariffs on all imports, from all countries, that could severely harm American consumers.”

The Biden administration has argued that a flood of low-cost exports from China is undermining American-made products, jeopardizing Biden’s push to expand American manufacturing, a central focus of his economic agenda.

In his speech, Biden said he would ask U.S. Trade Representative Katherine Tai to raise tariffs to what White House officials said would be 25 percent on certain Chinese goods that now face 7 percent tariffs. 5 percent, or none at all, on hold. the result of an administration review of tariffs on China initially imposed during the Trump administration.

“I want fair competition with China, not conflict,” Biden said, flanked by supporters and signs reading: “President Joe Biden: Standing with workers.” “And we are in a stronger competition to win the 21st century economic competition with China or any other country because we are investing in America and American workers again.”

The move is another effort by Biden to put up new barriers to trade with China in some industries. He could help him compete with Trump in a “tough on China” context with undecided voters, although administration officials said the election did not motivate the move.

A day earlier, Biden began a three-day tour of Pennsylvania, a crucial battleground state, by giving a speech in Scranton in which he focused on the tax code but repeatedly attacked Trump and accused him of favoring the billionaires on workers. class.

However, Biden’s plans on Chinese trade are more specific than Trump’s. The former president has called for broad and high new tariffs on imports from China and elsewhere, in a potential effort to fracture trade lines between the countries. The Biden administration is reviewing existing tariffs and is expected to propose raising some rates on Chinese goods and reducing others.

At a morning breakfast stop on the way to Pittsburgh from Scranton, Biden was asked by reporters if he was worried about a trade war with China. “There is no trade war,” he responded.

Before Biden’s remarks, Tai announced that his office had launched an investigation into China’s aggressive support for shipbuilders and other related industries, in response to a union complaint.

“The American commercial shipbuilding industry is a shell of its former self,” the unions wrote in a document submitted to the trade representative. They added: “The biggest obstacle to the industry’s recovery is the unfair trade practices of the world’s largest shipbuilding nation: China.”

In the complaint, the unions cite “hundreds of billions” of dollars in Chinese government support for the shipbuilding industry. These include the provision of steel by state-owned enterprises at below-market prices, along with a variety of efforts to target low-cost loans and other financing to shipbuilders by state-owned enterprises. Ms Tai called the allegations “serious and worrying”.

The measures threaten to deepen a trade dispute with Beijing, which has criticized Biden for his own efforts to subsidize American manufacturing, including tax credits in the Inflation Reduction Act that are intended to increase production of solar panels, vehicles electric and other technologies aimed at reducing fossil fuel emissions.

China’s Ministry of Commerce sharply criticized the investigation in a statement, saying it was “filled with a large number of false accusations, misinterpreting normal trade and investment activities as harmful to the national security and corporate interests of the United States, and blaming China for its own industrial problems.”

In his speech, Biden also reaffirmed his support for the steelworkers union in a dispute over the proposed sale of Pittsburgh-based US Steel to Japan’s Nippon Steel.

Japanese officials have promised to invest billions in American manufacturing facilities, keep US Steel’s headquarters in Pittsburgh and respect existing labor contracts. But the attempted purchase has drawn criticism from the union and a bipartisan group of senators, largely from industrial states, who say it could compromise national security.

Biden has voiced his opposition to the deal, which his administration is reviewing for security and antitrust concerns. He has repeatedly said that he will support the steelworkers in the dispute over the sale, although administration officials have not specified exactly what that means in terms of policy. In Pittsburgh, the president appeared to promise a worker that he would not allow the company to leave the United States, a move no one is currently discussing.

“Let’s keep US Steel in America,” one woman told Biden as he met with steelworkers before his speech.

“Guaranteed,” the president responded to cheers and applause.

David McCall, international president of the steelworkers union, praised Biden before his speech.

“President Biden promised USW members that he would stand with us,” McCall said. “And it is clear that this is the case.”

Biden and Trump are fighting for working-class votes in industrial swing states like Pennsylvania, Michigan and Wisconsin. Earlier on Wednesday, the Biden campaign released an ad featuring a steelworker touting Biden’s economic record and attacking Trump.

This week, Trump’s case over falsified business records began in Manhattan, the first of four criminal cases he faces that go to trial. Biden generally refrains from commenting directly on the trial. But his tour of Pennsylvania is intended to offer voters a contrast to Trump’s legal problems.

In his speech in Pittsburgh, Biden veiledly attacked Trump, referring to him as “my predecessor, who is busy right now.”

The crowd laughed and seemed to get the joke about Trump’s whereabouts, even though the former president doesn’t actually have to appear in court on Wednesdays.

Alexandra Stevenson contributed with reports.