Trump’s E.U. Tariffs Would Hobble Trade With U.S., Official Says

The European Union’s key trade negotiator warned on Monday that President Trump risked upending trans-Atlantic trade if he followed through on his latest tariff threat.

Maros Sefcovic, the E.U.’s trade commissioner, voiced frustration over Mr. Trump’s abrupt about-face on tariffs and threat — made public on Saturday — to impose a 30 percent levy on all goods from the 27-nation bloc starting next month. The announcement came after what Mr. Sefcovic said were frequent talks that he felt had the two sides “very close to an agreement.”

A tariff like the one that Mr. Trump has threatened would “prohibit” trade between the two closely intertwined economies, Mr. Sefcovic said as he walked into a meeting of European Union trade ministers in Brussels. He added that he planned to speak with his American counterparts later Monday to continue working toward a negotiated solution.

“We feel the huge responsibility for the biggest trading relationship on this planet,” he said. He added, “I cannot imagine walking away without genuine effort.”

But Mr. Sefcovic also made clear that the bloc’s negotiators were surprised and disappointed that their efforts to agree a deal had added up to so little.

Before Mr. Trump issued his threat last week, European officials had thought that they were closing in on a deal that was widely expected to include a 10 percent base line tariff, along with important carve-outs.

Mr. Sefcovic said that he spoke with his American counterparts “almost every other day” last week. “The feeling on our side was that we are very close to an agreement,” he said.

But Mr. Sefcovic said that he got a “heads up” just before Mr. Trump sent the letter blowing up those negotiations, and that had created a “totally different dynamic.”

Other ministers attending the meeting in Brussels expressed dismay at Mr. Trump’s latest tariff threat.

“We do not want any kind of trade war,” Lars Lokke Rasmussen, the foreign minister of Denmark, said. “It will be devastating, not just for the Americans, but also for Europe.”

Mr. Lokke Rasmussen added that it would be important to “flash some muscles,” suggesting that the bloc should be prepared to retaliate with its own tariffs against American imports, if needed.

Brussels has already prepared a list of U.S. products worth roughly 21 billion euros that the E.U. could hit with tariffs, and was in the process of finalizing a second list that would total more than 72 billion euros. Ursula von der Leyen, the president of the European Commission, made it clear on Sunday that those would be delayed from kicking in until Aug. 1 — but many European officials have insisted that it is important for the bloc to be prepared to hit back.

Some officials voiced support of the decision to wait.

“I don’t think this is weakness,” Mr. Lokke Rasmussen said. “It’s a clear signal that we don’t want to escalate things.”