Since U.S. President Joe Biden blocked this Japanese company's plan to acquire United States Steel for $14.1 billion, Nippon Steel's stock dropped on the first trading day on Monday. Biden has expressed opposition to the deal, formally announcing his decision on Friday, just days after the U.S. security review panel submitted the case to him. In a written statement, he noted that the acquisition would place a major Steel producer under foreign control, posing risks to critical supply chains. United States Steel and Nippon Steel stated in a joint statement that there was no evidence indicating a threat to National Security, asserting that the decision was political. They intend to challenge this order, which will be a difficult road and may significantly prolong the months-long struggle surrounding this U.S. industrial giant. This conflict has heightened tensions between the U.S. and its close ally, Japan. In early trading, Nippon Steel's stock price dropped 1.2% to 3,145 yen. The incoming president Donald Trump, who will take office later this month, has also vowed to block the agreement.