WASHINGTON — President Trump on Saturday threatened to hammer European automotive companies with steep tariffs as his global trade war rolled into a third day.
Trump, in a series of Twitter posts while at his Mar-a-Lago resort in Florida, appeared to be responding to warnings from European leaders that his promised tariffs on aluminum and steel would trigger retaliation from numerous major US trading partners.
Bring it on, the president seemed to say.
‘‘If the EU wants to further increase their already massive tariffs and barriers on US companies doing business there, we will simply apply a tax on their cars which freely pour into the US They make it impossible for our cars (and more) to sell there. Big trade imbalance!’’ Trump tweeted Saturday.
On Thursday, Trump shocked the world — and many of his top advisers — with an off-the-cuff announcement that the United States would impose a tariff of 25 percent on steel imports and 10 percent on aluminum imports.
Canada’s leaders said they would retaliate with tariffs on US exports, and European leaders said they would as well, targeting Kentucky bourbon, Harley-Davidson motorcycles, and blue jeans.
On Friday, Trump wrote in another Twitter post that ‘‘trade wars are good, and easy to win.’’ He also promised to enact what he called ‘‘reciprocal taxes’’ on any country that has a tariff against any US good or service.
His attack on European automakers is mostly aimed at Germany, which exported $23 billion in cars to the United States in 2016, according to data aggregated by Massachusetts Institute of Technology.
But large German automakers also have a sizable presence in the United States, with BMW employing thousands of workers in South Carolina and Volkswagen employing thousands more in Tennessee.
Those manufacturers produce hundreds of thousands of cars in the United States each year, many of which are later exported to buyers in Asia and Europe.
Trump often looks at trade relationships as a zero-sum game, complaining that the United States buys more goods and services from other countries than it sells to them. To that end, US firms sold $53 billion in exports and imported $118 billion in goods to Germany last year, the kind of dynamic that he has often opposed.
But critics of Trump’s approach have observed that tariffs and trade wars only drive up costs for domestic consumers, a move that would make German cars more expensive for US drivers.
Trump has also said these sorts of threats could incentivize foreign companies to expand their US operations, so they don’t have to pay the import fees.
Trump has been criticizing the German auto companies since before taking office, incensed at their move to expand production in Mexico and threatening them with a 35 percent tariffs on any cars brought into the United States.
Trump’s decision to seek steep tariffs on steel and aluminum imports has provoked rarely seen urgency among Republicans lawmakers, who are trying to persuade the president that he would spark a trade fight that could stall the economy’s recent gains if he doesn’t reverse course.
The issue pits Trump’s populist promises to his voters against the party’s free trade orthodoxy and the interests of business leaders, including major steel importers such as Boeing and General Motors.
Unlike recent immigration and gun policy changes that require legislation, Trump can alter trade policy by executive action. That intensifies the pressure on Republican lawmakers to change his mind before he gives his final approval for the penalties as early as this week.
While showing no sign of backing away Saturday, Trump also railed about ‘‘very stupid’’ trade deals by earlier administrations. He said other countries ‘‘laugh at what fools our leaders have been. No more!’’
House Speaker Paul Ryan, Republican of Wisconsin, called Trump after the president’s surprise announcement to urge the White House to reconsider the decision.
Senator Ben Sasse, Republican of Nebraska, and others have offered the president their own advice. Some are appealing to his desire for a robust stock market and warning that the trade penalties could unravel some of the gains they attribute to the tax bill he signed last year.
Republicans say the stakes are too high for them to sit back and wait for Trump to change his mind. Their public condemnation of the tariff plan was relentless.