Nippon Steel Corp. slumped the most in four months after a closely watched summit between US President Donald Trump and Japanese Prime Minster Shigeru Ishiba heightened uncertainty over the company’s plan to acquire United States Steel Corp.

President Donald Trump is suggesting that Nippon Steel will no longer buy U.S. Steel as planned, but the Japanese company will instead invest in the symbolically important American business.

President Trump supports the Japanese company’s taking a stake in the American steel maker after the U.S. blocked a $14 billion takeover bid.