Nippon Steel Corp. is stepping up efforts to win over U.S. workers and politicians for its $14.1 billion takeover of United States Steel Corp. despite stiff opposition from union leaders and the Biden administration.

Japan’s top steelmaker is sending Vice Chairman and Executive Vice President Takahiro Mori to Pittsburgh next week where he’ll meet with local staff and elected officials, said people briefed on the matter. It’s also dispatching technical teams to review U.S. Steel mills as the firm assesses how it can boost investment and labor commitments to convince union leaders and authorities of the deal’s merits, the people said.

Nippon Steel agreed to buy U.S. Steel in December, but opposition from the United Steelworkers and President Joe Biden has left investors uncertain of the deal’s fate. Biden last month vowed to keep U.S. Steel American-owned, in front of union workers ahead of November’s election.