Rear Adm. Brian Fort assumed command of U.S. Naval Forces Japan and Navy Region Japan (CNFJ/CNRJ) during a change-of-command ceremony Wednesday at a naval base in Yokosuka, Kanagawa Prefecture, amid growing regional tensions and concerns about the U.S.-Japan alliance, as well as questions of leadership and readiness following two fatal accidents involving American warships in 2017.

As the leader of U.S. naval forces in Japan, Fort's primary responsibility is to provide shore readiness to the fleet and oversee all shore installations and assigned forces of the U.S. Navy in Japan, while acting as a liaison to the Maritime Self-Defense Force.

The change of command also comes amid lingering concerns over U.S. commitment to Japan and the Asia-Pacific region after U.S. President Donald Trump's shocking criticism last month of the two allies' security treaty, which he blasted as "unfair."