U.S. inflation slowed last month for the first time since September even as additional tariffs on steel and aluminum kicked in Wednesday that could send prices higher.

Inflation slowed more than expected in February and cooled for the first time in four months, but that progress may be short lived as President Donald Trump ramps up his trade war, which threatens to increase prices for Americans.

American trading partners responded swiftly to President Trump’s latest round of levies with countermeasures, creating more uncertainty for C.E.O.s.

U.S. inflation slowed last month for the first time since September and a measure of underlying inflation fell to a four-year low.

U.S. inflation may have cooled a bit last month but it could be a short reprieve as President Donald Trump’s tariffs are widely expected to keep prices elevated in the coming months. On Wednesday, the Labor Department is expected to report that in February the consumer price index rose 2.