March 15 (Reuters) - U.S. Steel Corp said in a

regulatory filing on Friday that the acquisition by Nippon Steel ( NISTF )

is expected to close later this year.

The filing with exchanges comes at a time when the Japanese

firm's $14.9-billion deal to buy the iconic 122-year-old U.S.

steelmaker faces heightened scrutiny due to national security

concerns.

U.S. President Joe Biden on Thursday expressed explicit

opposition to the deal and said U.S. Steel must remain a

domestically owned American firm.

Cleveland-Cliffs CEO Lourenco Goncalves said on

Thursday he would consider another bid for U.S. Steel likely

worth no more than $30 per share if the Nippon Steel ( NISTF ) deal falls

apart.