The United Steelworkers (USW) has urged President Trump to block Nippon Steel's proposed acquisition of U.S. Steel, despite Nippon Steel's pledge of US$14 billion in investments.

In a statement released Thursday, following a national security panel's recommendation to Trump, the USW accused Nippon Steel of historical dumping practices in US markets. The union argued that the merger poses a threat to American national security and the domestic steel industry, saying that Nippon Steel simply wants to weaken the US domestic industry from within.