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.

U.S. Treasury Secretary Janet Yellen said on Wednesday that Nippon Steel's blocked acquisition of U.S. Steel received a "thorough analysis" by an interagency national security review body that was sent to President Joe Biden.

Nippon Steel and U.S. Steel are filing a federal lawsuit challenging the Biden administration’s decision to block a proposed nearly $15 billion deal for Nippon to acquire Pittsburgh-based U.S. Steel