Update 11:50: Adds response from United Steelworkers union.

American steel (NYSE:X) David Burritt said Wednesday that the company will close steel mills and possibly move its headquarters outside of Pittsburgh if its planned sale to Nippon Steel (OTCPK:NPSCY) (OTCK:NISTF) collapses. US Steel shares rose 2.6%.

In an interview for Wall Street JournalBurritt said Nippon Steel (OTCPK:NPSCY) (OTCPK:NISTF) has committed to investing nearly $3 billion in US Steel (X)’s legacy mills, which is critical to keeping them competitive and preserving employee jobs.

“We wouldn’t have done this if the deal hadn’t happened,” Burritt said. WSJ. “I have no money.”

The CEO also said in the interview that Nippon Steel (OTCPK:NPSCY) (OTCPK:NISTF) would bring investment and the latest steelmaking technology to U.S. Steel’s (X) legacy mills in Gary, Indiana, and Mon Valley Works near Pittsburgh, and called opposition to the proposed takeover by the Japanese company “puzzling and confusing.”

“To date, Burritt has described USS as a world-class steel company, but now he is making baseless and unlawful threats, saying that if the Nippon deal is rejected, US Steel’s future as a viable steel company will be in jeopardy,” United Steelworkers President Dave McCall said in a statement Wednesday. “His reckless statements and mismanagement are the only real obstacles to US Steel remaining a sustainable steel company.”

Democratic presidential candidate Kamala Harris said earlier this week that U.S. Steel (X) should remain a domestic company and be run by a domestic company; President Biden, Republican presidential candidate Donald Trump, several members of Congress and the United Steelworkers union have also spoken out against the deal.

Nippon Steel (OTCPK:NPSCY) (OTCPK:NISTF) said on Wednesday that if the deal goes through, US Steel (X) would remain an American company headquartered in Pittsburgh and its board would be composed primarily of Americans.