With US foreign policy in flux, Japan and South Korea are finding common ground on trade, defense, and demographic challenges.

On his first official visit to Japan since taking office in June, Lee met Ishiba at the premier's residence in Tokyo to discuss bilateral ties between the East Asia neighbours, including closer security coordination with the United States under a trilateral pact signed by their predecessors.

Trump elaborated later Monday that he was referring to raids on churches and on a U.S. military base by the new South Korean government, which they “probably shouldn't have done,” the president argued.