The United States Steel board of directors issued a rare public letter reaffirming its commitment to the buyout by Nippon Steel. The letter accuses rival Cleveland-Cliffs of spreading false rumors to derail the US$14.1 billion deal.

Approved by US Steel shareholders in April, the takeover faces opposition from the United Steelworkers union. US Steel claims Cleveland-Cliffs is misleading the market into thinking the company is reconsidering the transaction.

The board emphasized that it evaluated proposals from both Cleveland-Cliffs and Nippon Steel, finding the Japanese firm's offer superior. US Steel believes the Nippon deal benefits shareholders and the economic security of the United States.

In response, Cleveland-Cliffs denied spreading misinformation and highlighted the union's support for its own proposal.