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

The United States and Japan have struck a trade deal to reduce the tariffs placed upon Japanese goods imported into the U.S. Despite this, though, Japanese automakers are worried about the current state of play.

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.