March 27 (Reuters) - Nippon Steel 5401.T and U.S. Steel X.N are in active talks about a deal that would preserve their $14 billion merger and secure billions more in investments from the Japanese steelmaker into Rust Belt facilities, Semafor reported on Thursday.

In recent meetings with White House officials, Nippon has offered to increase the $2.7 billion it had previously offered to upgrade U.S. Steel factories to as much as $7 billion, the report said, citing people familiar with the matter.

Nippon Steel and U.S. Steel did not immediately respond to Reuters' requests for a comment.

Nippon Steel President Tadashi Imai on Monday told reporters that Japan's biggest steelmaker and U.S. Steel will continue negotiations with the U.S. government to reach an agreement on the terms of the equity purchase and future investment plans.

In February, U.S. President Donald Trump, alongside Japanese Prime Minister Shigeru Ishiba at the Oval Office, said that Nippon Steel's $14.9 billion bid for U.S. Steel would take the form of an investment instead of a purchase.

Trump also said in mid-February that he would not mind if Nippon Steel took a minority stake in U.S. Steel.

Nippon Steel, the world's fourth-biggest steelmaker, made a $14.9 billion bid for U.S. Steel in December 2023, ultimately promising billions of dollars in investment to revamp its aging infrastructure and pledging to keep its headquarters in Pittsburgh, Pennsylvania.