06:24 AM EST, 12/03/2024 (MT Newswires) -- United States Steel's ( X ) proposed takeover by Japan's Nippon Steel will be opposed by President-elect Donald Trump once he takes office, Trump said in a Truth Social post.

"I will block this deal from happening. Buyer Beware!!!" Trump wrote on Monday, further adding that he will introduce a series of tax incentives and tariffs to make US Steel "strong and great again."

Nippon Steel said Tuesday it plans to invest more than $2.7 billion in US Steel's steelworks, as the deal will "help strengthen" the US industry and supply chains.

US Steel did not immediately respond to MT Newswires' request for comment.

The company's shares were down over 7% in recent Tuesday premarket activity.