WASHINGTON (Reuters) -The United Steelworkers union urged U.S. President Donald Trump on Thursday to block Nippon Steel's ( NISTF ) bid for U.S. Steel despite a pledge by the Japanese steel giant to invest $14 billion in the iconic American company, as first reported by Reuters.

In a statement published a day after a powerful national security panel submitted a fresh recommendation on the deal to Trump, the union said, "Now, as it continues to make flashy promises about proposed investments, it remains clear Nippon is simply seeking to undercut our domestic industry from the inside."

Nippon Steel ( NISTF ) and U.S. Steel did not immediately respond to requests for comment.