President-elect Trump has also opposed Nippon Steel's $15 billion acquisition of U.S. Steel, which President Biden blocked last week.

A 123-year-old steelmaker’s fate could yet become a restraint on modern-day executive power. United States Steel and suitor Nippon Steel have gone to court over U.S. President Joe Biden’s decision to nix their $15 billion deal.

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.

The companies argued in a lawsuit announced on Monday that Biden violated the Constitution by blocking the merger via a sham national security review that deprived the companies of their right to a fair process.

The blocked merger between Nippon Steel and U.S. Steel has entered legal proceedings, following intervention by President Joe Biden. Treasury Secretary Janet Yellen stated that the Committee on Foreign Investment in the United States (CFIUS) conducted a thorough analysis before advising the President,

President Joe Biden has rejected the nearly $15 billion proposed deal for Nippon Steel of Japan to purchase Pittsburgh-based U.S. Steel.

In dual lawsuits filed Jan. 6, U.S. Steel Corp. and Nippon Steel Corp. blame the Biden administration's politicizing its national-security review as well as the behind-the-scenes actions by rival Cleveland-Cliffs Inc. and United Steelworkers International President David McCall for scuttling the $14.9 billion deal.

President Joe Biden officially announced on Friday he has blocked Nippon Steel's $14.1 billion purchase of U.S. Steel, setting up a likely federal court battle.

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.

U.S. President Joe Biden’s decision to reject a bid by Nippon Steel to acquire U.S. Steel on national security grounds isn’t the first time friction over trade and investment has irked Washington’s closest ally in Asia.

U.S. President Joe Biden’s decision to reject a bid by Nippon Steel to acquire U.S. Steel on national security grounds isn’t the first time friction over trade and