TOKYO, Sept 24 (Reuters) - Nippon Steel ( NISTF ) Vice

Chairman Takahiro Mori said on Tuesday the Japanese company

remains committed to talks with the United Steelworkers (USW)

labour union over its bid to acquire U.S. Steel.

Mori, the key negotiator of the $14.9 billion buyout deal,

said USW President David McCall "has not seriously considered

any of the proposals that we have presented" in a letter to the

U.S. Steel employees.

"We just need USW leadership to come to the table. I am

hopeful they will do so in the very near future," Mori wrote.

The USW did not immediately reply to a Reuters request for a

comment.

The deal has faced opposition from high-profile

Democrats and Republicans ahead of the U.S. November

presidential elections, including from Democrat candidate Kamala

Harris and her Republican competitor Donald Trump.

Sources told Reuters last week the U.S. national security

panel reviewing the deal let the companies refile their

application for approval, delaying a decision on the politically

sensitive merger until after the Nov. 5 presidential election.

In the letter, Mori said Nippon Steel ( NISTF ) was committed to

maintaining U.S. Steel's blast furnace operations for the long

term and that it will not use slabs made overseas instead of

slabs made in USW-represented U.S. Steel facilities.

The Japanese company will honour all U.S. Steel's

commitments related to the union's agreements, including in

labour, pension and insurance, Mori said, adding that his

company will not interfere with U.S. Steel's decisions on trade

matters.

The companies plan to close the deal by the end of December,

pending regulatory approvals.

(Reporting by Kaori Kaneko, Kantaro Komiya and Katya Golubkova;

Editing by Jacqueline Wong and Lincoln Feast.)