"The U.S. measures are not in accordance with international trade rules and are extremely regrettable," Japan's aluminum industry association said in a statement.

"Imports of aluminum from Japan, a U.S. ally, are not affecting U.S. national security at all," the body said.

The comments came after U.S. President Donald Trump pressed ahead with the imposition of a 25 percent tariff on steel imports and 10 percent for aluminum on Thursday, but exempted Canada and Mexico.

(Reporting by Yuka Obayashi; Editing by Tom Hogue)