Japan needs to empower females in the workplace and promote male participation in child-rearing in order to address its falling birthrate, the head of the United Nations Population Fund (UNFPA) said.

"If they (women), for instance, leave to go and have a baby, they don't lose promotion, they don't lose anything, and then when they come back, they can also look after their children whilst they are working, and then men's participation in that also tends to ensure that you facilitate growth in population," Babatunde Osotimehin, the UNFPA's executive director, said Tuesday in a telephone interview.

He added that it was important for women's workplaces to have child care facilities so they can continue working after giving birth and do not lose opportunities to advance their careers.