By Kevin Buckland and Kiyoshi Takenaka TOKYO (Reuters) -Japan Prime Minister Shigeru Ishiba asked U.S. President Joe Biden to allay concerns in the Japanese and U.S. business communities over the status of Nippon Steel's planned acquisition of U.

TOKYO -- Nippon Steel's plan to buy U.S. Steel has entered a new phase with the companies' declaration of a full-scale legal war against the U.S. government. They hope the lawsuits will overturn President Joe Biden's order to give up the acquisition.