The onetime dynamo is fighting to revive a takeover by Nippon Steel. Other tie-ups could also face obstacles, and going it alone could force cutbacks.

Separate lawsuits from Nippon Steel and U.S. Steel target President Joe Biden as well as a steelworkers union head and a rival steelmaker’s CEO.

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

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.

The usually reticent ally is making it clear that it will not go quietly in its fight to overturn President Biden’s decision to block Nippon Steel’s $14.1 billion takeover bid of U.S. Steel, with Prime Minister Shigeru Ishiba warning this week that the rejection could have real consequences for the bilateral relationship,

President Joe Biden last week capitulated to uneconomic thinking by blocking Nippon Steel’s purchase of U.S. Steel. That decision will ultimately harm Minnesota’s Iron Range.

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