GARY, Ind. (WLS) — Leaders in Northwest Indiana reacted Friday after President Joe Biden decided to block Japan’s Nippon Steel from acquiring U.S. Steel.

The U.S. Steel smokestacks along the lakefront are a prominent landmark for the city of Gary. The company, with its more than century-long history in Gary, is the city’s largest employer with nearly 5,000 jobs.

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Gary Mayor Eddie Melton has been a big supporter of the proposed $15 billion merger between U.S. Steel and Japan’s Nippon Steel.

“Gary has seen a significant downturn over the last 50 years,” Melton said. “As we are constantly rebuilding from within, we couldn’t risk losing one of our largest employers.”

The Gary mayor said during a visit last month, Nippon executives promised a $1 billion investment in the Gary plant, replacing the four blast furnaces over the next ten years. However, union leaders support President Biden’s decision to block the deal, citing concerns about the long term stability of the steel industry.

“The president took action to block the deal so U.S. Steel remains a proud American company, American-owned, American-operated by American Union steel workers and the best in the world,” White House Press Secretary Karine Jean-Pierre said.

Northwest Indiana congressman Frank Mrvan also agrees, saying in a statement, “It is absolutely right to prevent a foreign company with proven trade abuses from controlling our domestic steel production.”

The companies, however, are vowing to fight the President’s decision, saying, “Blocking this transaction means denying billions of committed investment to extend the life of U.S. Steel’s aging facilities and putting thousands of good-paying, family-sustaining union jobs at risk. In short, we believe that President Biden has sacrificed the future of American steelworkers for his own political agenda.”

Gary’s mayor agrees.

“Yesterday we had a potential deal in hand. Today we have nothing,” Melton said. “So it’s uncertain what the future’s gonna be.”

A White House spokesperson said the president’s decision has nothing to do with Japan, a close ally of the United States.

In the meantime, a spokesperson for U.S. Steel says they do intend to pursue their legal options, but it’s unclear exactly what that means.