The White House factsheet on the trade deal mentions that Japan will also buy 100 Boeing Co. planes as well as US defense equipment worth additional billions of dollars annually. Akazawa said both these pledges were based on existing plans by Japanese airlines and the government, respectively.

The new U.S.-Japan trade deal lowers tariffs and strengthens economic ties, helping challenge China's regional aggression and instability.

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.