Former defence minister Itsunori Onodera, speaking in Washington at the Center for Strategic and International Studies, expressed particular concern about the potential impact on Southeast Asia.
South Korea, together with Hong Kong, Macau and Puerto Rico, is one of only a few places in the world with a fertility rate below 1, data by the World Bank shows, Statista reports.
Moscow has in recent decades made repeated moves to bully Japan into remaining silent on a number of territorial issues, most famously over possession of the Kuril Islands east of Hokkaido.
The global economic system under which most countries have operated for the last 80 years is being reset, ushering the world into a new era.