(Reuters) - Nippon Steel ( NISTF ) will not import steel to the U.S. from its international mills, the Japanese company's Executive Vice President Takahiro Mori said on Monday in a letter to United Steelworkers union members.

Nippon is looking to close its $14.9 billion deal for U.S. Steel by the end of the year before President-elect Donald Trump, who has pledged to block the deal during his campaign, enters the White House in January.

In its effort to ease the challenges posed by the union and President Joe Biden, the company has pledged investments to US Steel and assured job security to the United Steelworkers union.

It has also promised to sell a stake in a U.S. steel plant joint venture if the company succeeds in the buyout.

In his letter, Mori reiterated the promises made over the past year and addressed concerns raised by union leaders, including USW President David McCall.

"We are here to inform you, not to negotiate as President McCall has suggested. I have asked President McCall to meet, most recently on November 11. I await his response," Mori said.

In September, an arbitration board jointly selected by the company and the USW, ruled in favor of the deal, but the union disagreed with the decision.

Mori, who is scheduled for a U.S. visit next week, will meet steelworkers in Pittsburgh and also visit New York and Washington.

The Japanese steel company is making efforts to finalize the deal, as the Committee on Foreign Investment in the United States has extended its review until the end of December.

(Reporting by Aatreyee Dasgupta in Bengaluru; Editing by Mohammed Safi Shamsi and Arun Koyyur)