WASHINGTON, April 10 (Reuters) - U.S. Steel and Nippon Steel 5401.T are working closely with the Trump administration "to secure a significant investment," U.S. Steel X.N said on Thursday, after remarks from President Donald Trump dimmed hopes for a greenlight of the companies' long-sought tie-up.

Trump said on Wednesday he did not want to see U.S. Steel "go to Japan," sending its shares down 7% amid fears his comments signalled renewed reservations about Nippon's $14 billion bid for the 124-year-old American firm.

U.S. Steel's statement suggested the company remained positive about the deal. The White House did not immediately respond to requests for comment. Nippon Steel declined comment.

The deal, announced in December 2023, has faced headwinds from the start. Both former President Joe Biden and Trump last year asserted that U.S. Steel should remain American-owned as they sought to win over voters in the swing state of Pennsylvania, where the company is headquartered, during a hotly contested election.

In January 2025, Biden blocked the transaction on national security grounds. But the parties quickly sued, alleging they were denied a fair national security review, because Biden had prejudiced the process via his public opposition to the deal in a bid to win reelection.

Trump, who took office for the second time on January 20, began his term noting that he "wouldn't mind" if Nippon Steel took a minority stake in U.S. Steel, implying he would seek a dramatic overhaul of the deal structure.

But his government's recent actions boosted hopes for approval of a full takeover.

On Monday, Trump directed the Committee on Foreign Investment in the United States, which reviews foreign investments for national security risks, to take a fresh look at the all-cash bid for U.S. Steel to help determine if "further action" would be appropriate.

The same day, his 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 Alexandra Alper in Washington; Editing by Nia Williams)

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