Nippon Steel Chief Executive Eiji Hashimoto says the top Japanese steelmaker is standing firm on its proposed $15 billion acquisition of U.S. Steel.

Eiji Hashimoto is getting his samurai on — riding into battle against both the outgoing and incoming U.S. presidents.

U.S. Steel and Japan’s Nippon Steel sued the United States government on Monday in a last-ditch attempt to revive their attempted merger after President Biden blocked it last week on the basis that the transaction posed a threat to national security.