Japan's unemployment rate rose in January from a month earlier, the government said in a report on Friday.

According to the Ministry of Internal Affairs and Communications, the unemployment rate came in at at 2.5 percent in January, jumping 2.4 percent from December's reading.

Separately, the Ministry of Health, Labor and Welfare said the job availability ratio was flat in December at 1.63 from the previous month.

The figure converts to there being 163 job openings for every 100 people seeking employment.

This reflects Japan's increasingly tight labor market as the nation's demographic crisis sees fewer working-aged people amid a rapidly graying population.