Since then, however, several U.S. lawmakers have come out in opposition to the deal, citing national security concerns. President Joe Biden has said U.S. Steel must remain a domestically owned American firm. U.S. Steel's shares closed down 2.1% at $41.33 on Friday, well below Nippon Steel's offer of $55 a share, reflecting uncertainty over whether the deal will secure regulatory approval. The deal has drawn strong criticism from the United Steelworkers (USW) labor union, which is worried about potential job losses.