The deal, which would set a 15 percent tariff on most E.U. goods, averted what could have become a painful trade war with the United States’ biggest source of imports. “We are agreeing that the tariff straight across for automobiles and everything else will be a straight-across tariff of 15 percent.

President Trump said he reached a trade agreement on Sunday with the European Union, avoiding a damaging trade war with the U.S.’s largest trading partner and marking his biggest deal so far in his attempt to remake the global trading system through higher tariffs for U.S. trading partners.