President-elect Donald Trump says he will use a series of tax incentives and tariffs to block Nippon Steel's planned $14 billion purchase of U.S. Steel.
In a social media post, Donald Trump said he is "totally against... U.S. Steel being bought by a foreign company."
At the same time, Nippon Steel is looking to close the deal before Mr. Trump is sworn in next month, although President Joe Biden and the United Steelworkers union also oppose the takeover.
Mr. Biden referred the deal to a government panel that reviews foreign investments.
By next month the panel could approve the deal, suggest the president block the transaction, or extend the review.
Last week, Japan's prime minister called on President Biden to approve the purchase.