The CEO of Cleveland-Cliffs – a Nippon and U.S. Steel competitor – argues suing his company and the Biden administration is "a bad idea" as the billion-dollar deal was legally blocked.

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 Japanese firm’s planned purchase of its U.S. rival was blocked last week by President Joe Biden after a year of diplomatic tension, political debate and lobbying efforts from the companies and unions. Biden, who had previously said he opposed the tie-up, cited national-security risks, despite Japan being a close ally.