12:14 PM EST, 12/03/2024 (MT Newswires) -- (Adds comment by US Steel beginning in the third paragraph and stock price updates in the first and final paragraphs.)

United States Steel ( X ) shares were extending their decline on Tuesday after President-elect Donald Trump vowed on Monday to scuttle the proposed acquisition by Japanese rival Nippon Steel after he takes office next month.

"I will block this deal from happening. Buyer Beware!!!" Trump wrote in a Truth Social post Monday night, adding he plans to introduce a series of tax incentives and tariffs intended to make US Steel "strong and great again."

In a statement provided to MT Newswires, US Steel said on Tuesday the deal with Nippon Steel, "provides, by far, the brightest future" for the company as well as its employees and customers.

The company continued to emphasize what it believes are the key benefits of the proposed acquisition, including plans by Nippon Steel to invest $2.7 billion to upgrade US Steel facilities in Pennsylvania and Indiana along with a commitment to keep the company based in the US after the buyout closes.

"No other party can do this," it said.

US Steel shares recently were down nearly 8% in midday trading. recovering modestly from a 10% slide earlier Tuesday.

Price: 37.70, Change: -3.25, Percent Change: -7.94