By Andrea Shalal and Chris Sanders

WASHINGTON (Reuters) -Shares of U.S. Steel plunged 11% in premarket trading on Thursday after U.S. President Donald Trump - in a contradiction from previous White House actions - said on Wednesday that he does not want the steel producer to go to Japan, suggesting he does not support Nippon Steel's ( NISTF ) $14 billion bid.

Trump's comments were the latest in a series of confusing pronouncements in the long-running saga over Nippon's pursuit of U.S. Steel. Trump opposed the deal during the 2024 campaign, but has warmed to it since.

On Monday, he directed a national security panel to take a fresh look at the all-cash bid for U.S. Steel to help determine if "further action" is appropriate, raising hopes the deal could gain an elusive green light.

Since returning to the White House, Trump's on-again, off-again approach to commerce has spooked business executives, who say the uncertainty has made it difficult to model for the future.

The administration has taken a heavy hand in the negotiations around the possible sale of China-based ByteDance's TikTok, but that deal has seen little progress. The back-and-forth on policy has also clogged dealmaking and business activity.

U.S. Steel shares lost $5.01 to $40.09 on Thursday. They remained well below Nippon Steel's ( NISTF ) $55 a share offer price.

"We don't want to see it go to Japan," Trump said, adding "We love Japan."  

"We don't want it to go to Japan or any other place, and we're working with them," Trump said.

The comment shows the future of the deal remains uncertain given sudden changes in thinking at the White House. 

White House officials gave no details about Trump's comments or whether they contradicted Monday's action. "Everything's always on the table with the president," one official said.

U.S. Steel and Nippon Steel ( NISTF ) did not respond to requests for comment.

Outgoing President Joe Biden had blocked the merger in January on national security grounds.

After Biden's decision, the two companies sued the Committee on Foreign Investment in the United States (CFIUS), which scrutinizes foreign investments for national security risks, alleging Biden had prejudiced the committee's decision and violated the companies' right to a fair review.

The deal was announced in December 2023 and almost immediately ran into opposition across the political spectrum ahead of the November 5 U.S. presidential election. Both then-candidates Trump and Biden vowed to block the purchase of the storied American company.

The companies had argued that Biden opposed the deal when he was running for reelection to win support from the United Steelworkers union in the battleground state of Pennsylvania, where U.S. Steel is headquartered. The Biden administration had defended the review as essential to protecting security, infrastructure, and supply chains.

Last month, the Trump administration filed a motion to extend two deadlines in the lawsuit to give the government more time to wrap up merger talks with the firms.

Late on Monday, the Trump administration and the companies asked an appeals court to pause their litigation until June 5 while CFIUS reviews the tie-up again, noting that the process has the potential to "fully resolve" the companies' claims. 

(Reporting by Andrea Shalal in Washington; Editing by Scott Malone, Bill Berkrot, Jamie Freed and Anil D'Silva)