By John Geddie, Tim Kelly and Yuka Obayashi

TOKYO (Reuters) -Snow lay thick in the Pittsburgh suburbs as Takahiro Mori, a bespectacled, 67-year-old executive from Japan's Nippon Steel, huddled in a cluttered garage with community leaders to reassure them he was not giving up on a bid to buy the town's steel mill.

Just days before the early January meeting, U.S. President Joe Biden had blocked Nippon Steel's proposed $14.9 billion takeover of U.S. Steel, a move both companies said risked thousands of jobs and billions of dollars in investment.

With Biden's incoming successor Donald Trump also voicing opposition to the planned purchase, the outlook was bleak.

Fast forward five months and the persistence shown by the firm's chief negotiator seems set to pay off, with Trump now signalling he is prepared to support a deal.

"It's been a long, hard battle," said Chris Kelly, the 70-year-old mayor of West Mifflin who hosted Mori for the January meeting at his garage-cum-office on a suburban residential street near U.S. Steel's ageing Irvin plant.

He said he has met Mori on several occasions since Nippon Steel's bid was first unveiled in late 2023, including at an American football game and a Pittsburgh restaurant just over a week ago when the Japanese executive flew in to give an update on the latest developments of the planned takeover.

Nippon Steel declined to comment on the meetings.

Mori, a 40-year company veteran, has been the public face of Nippon Steel's extensive efforts to convince local workers, officials and U.S. lawmakers of the economic merits of a merger plan that has had to weather a political firestorm.

"I just have a strong desire to make this work somehow," a calm and smiling Mori, who serves as the company's vice chairman and executive vice president, told Reuters in an interview last week when asked about how he had personally endured the saga.

Mori said he had made around 10 trips to the United States since the start of the year alone, visiting steel towns and Washington DC, where lawmakers have been deliberating over any potential national security risks posed by the transaction.

"On the plane to the destination, I can hardly sleep," he said, explaining that he had to read reams of documents, prepare for meetings during the flight, and work through the night to manage tasks back in Japan.

There may still be twists ahead. While Trump has said he supports a "planned partnership" between the two companies, lingering questions remain about the scope of the deal and its costs for the Japanese firm.

HIGH STAKES

For Japan's top steelmaker, U.S. Steel is central to its global expansion strategy at a time when domestic demand is declining.

A merger would create the world's third-largest steel producer by volume, after China's Baowu Steel Group and Luxembourg-based ArcelorMittal, according to World Steel Association data.

While Mori has had a hand in the firm's overseas expansion efforts in places like Brazil and India, the acquisition of a company centred in the critical swing state of Pennsylvania in an election year presented unique challenges.

As soon as the agreement was announced in December 2023, the politically-influential United Steelworkers union issued a statement condemning U.S. Steel for selling the storied American firm to a foreign-owned company.

Within weeks, Biden had joined his election challenger Trump in saying he was against the deal, subjecting it to the first of two rounds of national security reviews by the secretive Committee on Foreign Investment in the United States.

Just before Trump signalled support on Friday, the union issued a statement alleging Nippon Steel was "a serial trade cheater" and that the sale would be "a disaster" for American steelworkers.

In an interview with Reuters in December, union chief David McCall, said he was frustrated by what he said was the Japanese company's refusal to give assurances about their long-term commitment to the company and its workers. However, he described Mori, his opposite man in those talks, as "personable".

What appears to have swung the deal back in Nippon Steel's favour with the transactional Trump is money.

The firm has plans to invest $14 billion in U.S. Steel's operations, including up to $4 billion in a new steel mill, Reuters exclusively reported last week.

But on the ground in Pittsburgh at least, the persistence and personal touch of Mori, who obtained a masters degree from the University of Pennsylvania's Wharton School in 1992, has also left an impression on some of those he has met.

"They've embraced everything about the city of Pittsburgh," said Kelly, the mayor, recounting that Mori was yelling and waving a towel in support when the pair attended a match for the local Pittsburgh Steelers American football team last year.

(Reporting by John Geddie, Tim Kelly and Yuka Obayashi in Tokyo; Editing by Kate Mayberry)