Tokyo, July 29 -- Japan's population of Japanese nationals has fallen below the 120 million mark for the first time in 42 years, underscoring a deepening demographic crisis driven by a falling birth rate, news agency Kyodo News reported, citing data from the Ministry of Internal Affairs and Communications.

According to figures released by the ministry, the number of Japanese citizens stood at 119,736,483 as of January 1, marking a decline of 917,000 from the previous year. This represents the sharpest drop recorded since comparable data collection began in 1968.

In contrast, the population of foreign residents expanded by 354,000 to reach a record 4,031,159. The ministry has been tracking statistics on non-Japanese residents since 2013....