TOKYO, July 3 (Reuters) - Nippon Steel's ( NISTF ) vice

chairman plans to return to the United States next week again to

discuss its proposed acquisition of U.S. Steel, a company

spokesperson said on Wednesday.

The planned visit by Takahiro Mori, the Japanese firm's key

negotiator for the deal, follows trips to the U.S. in May and

June, highlighting the importance of the $15 billion takeover

offer to the world's No. 4 steelmaker.

U.S. Steel's management has backed the bid but the deal

faces resistance from the White House and the powerful United

Steelworkers (USW) union.

Nippon Steel ( NISTF ) declined to provide further details of Mori's

next visit. According to a source familiar with his travel plans

who declined to be identified, Mori will travel to several

states where U.S. Steel has operations and meet with local

officials, community leaders and workers.

On his last trip, Mori met with U.S. Steel employees and

community leaders to gain a better understanding of their views

and saw a positive reaction, the company said.