When President Donald Trump revealed that his administration had struck a "massive" trade and investment deal with Japan, he described it as "completed"—but it must still pass the Japanese parliament, called the Diet, which is riven with political turmoil.

Japan's government said on Friday that profits from a $550 billion investment package agreed in this week's tariff deal with the U.S. would be split between Japan and the U.S. according to the degree of contributions by each side.