WASHINGTON, April 18 (Reuters) - Any national-security review of the deal by for U.S. Steel conducted by the Committee on Foreign Investment in the United States (CFIUS) will proceed as normal, a White House official said on Thursday.

President Joe Biden has repeatedly said he opposed the sale of the U.S. industrial firm to Japan's Nippon Steel, leaving some to describe the deal as on life support. But it remained unclear what, if any, additional steps he would take to block the deal.

"Obviously, there are certain legal processes... you're referring to CFIUS," said White House National Economic Adviser Lael Brainard at the Semafor World Economy Summit 2024. "Those are going to proceed as normal, presumably."

Speaking on Wednesday to steel workers, Biden promised that U.S. Steel would remain a "totally American company." U.S. Steel and Japanese buyer Nippon Steel later said the Pittsburgh-based firm will remain an "iconic American company" even after the $14.9 billion takeover.

United States Steel shares were trading down 0.3% at $39.02 midday Thursday, and Nippon Steel shares closed up 0.9% to 3,463 yen in Tokyo. (Reporting by Trevor Hunnicutt and Doina Chiacu Editing by Nick Zieminski)