UPDATE 1-Three Republican senators oppose Nippon-U.S. Steel deal over national security

Three U.S. Senators have urged Treasury Secretary Janet Yellen to block the $14.9 billion acquisition of U.S. Steel by Japan's Nippon Steel , citing national security. Nippon clinched a deal on Monday to buy U.S. Steel for $14.9 billion in cash, prevailing in an auction for the 122-year-old iconic steelmaker over rivals such as Cleveland-Cliffs, ArcelorMittal and Nucor. "Despite the absence of any security-focused deliberation on U.S. Steel's part, domestic steel production is vital to U.S. national security," according to the letter on Tuesday from Republican Senators JD Vance, Josh Hawley and Marco Rubio.