WASHINGTON (AP) — President Joe Biden has blocked the nearly $15 billion proposed deal for Nippon Steel of Japan to purchase Pittsburgh-based U.S. Steel — affirming his earlier vow on the presidential campaign trail to prevent the acquisition of Steeltown USA’s most storied steel company.

The president said he was moving to protect national security in deciding the fate of the iconic Pennsylvania-based company, which became a contentious political issue in an election year.