TOKYO, Jan 15 (Reuters) - Japan's Nippon Steel ( NISTF )

remains interested in working with the incoming administration

of Donald Trump to try to seal a takeover of U.S. Steel,

its vice chairman Takahiro Mori said an opinion piece in the

Wall Street Journal.

Last week, Nippon Steel ( NISTF ) and U.S. Steel filed two lawsuits

after U.S. President Joe Biden blocked a $14.9 billion buyout of

the American steelmaker by the Japanese firm. President-elect

Donald Trump takes office on Monday.

Enforcement of Biden's order, which gave the parties 30 days

to unwind the transaction, was postponed until June after the

companies sued the U.S. president, alleging he violated the

constitution by depriving them of due process when he blocked

the deal.

"Nippon Steel ( NISTF ) and U.S. Steel will do whatever it takes to

close this transaction," Mori said in the WSJ piece. "We believe

our case is strong, and we look forward to our day in court."

Cleveland-Cliffs ( CLF ), whose earlier bid for U.S. Steel

was rejected by the latter's board, is partnering with peer

Nucor ( NUE ) to prepare a potential all-cash bid for the

company again, a source told Reuters this week.

"We remain interested in exploring possible partnerships

with the new administration to invest in and grow U.S. Steel to

benefit American workers, customers, and national security,"

Mori, Nippon Steel's ( NISTF ) key negotiator on the deal, said in the

opinion piece.

The decision to file lawsuits was not taken lightly, Mori

said, while reiterating that Japan is one of U.S. closest allies

and the company did not believe there was any national security

concern regarding the takeover.

"Major companies in allied nations want to invest in the

U.S. and employ Americans. Now they wonder if they'll be treated

as partners or political pawns," Mori said.