Global trade turmoil deepened on Wednesday as the European Union announced up to about $28 billion in retaliatory tariffs on U.S. exports, shortly after President Trump’s across-the-board levies on steel and aluminum imports took effect. The latest escalations in the trade war instigated by Mr. Trump came hours before the release of the latest reading of the U.S. Consumer Price Index, which eased more than expected in February, a modest but welcome sign amid rising concerns about the effects of President Trump’s trade policies. Mr. Trump has appeared undeterred by the uncertainty and fear that his tariffs, against friends and foes alike, have injected into the global economy. He has not ruled out the possibility that his policies could cause a recession in the United States. The European Union said its retaliatory tariffs, which would take effect April 1, were proportionate to about $26 billion in tariffs applied by the United States. But European officials, already facing a lackluster economy, emphasized that they were ready to strike a deal with the Trump administration. “Jobs are at stake, prices up — nobody needs that,” said Ursula von der Leyen, president of the European Commission. No other countries immediately announced further retaliation. China did not directly address the U.S. tariffs, although its Foreign Ministry spokeswoman said the government would take “firm measures” to safeguard its interests. The 25 percent tariffs on imports of steel and aluminum have the support of U.S. domestic producers. But they could hit a range of industries, including car manufacturing, and potentially slow down the American economy.