Population aging and productivity are two major challenges facing Asia

Lagarde, the IMF's president, said on Wednesday that population issues and productivity are two major challenges for Asia's economy to achieve sustainable growth.

Lagarde said in a seminar in Tokyo that Japan, South Korea and China will need to take measures to tackle the problem of rapid population aging.

She said improving productivity is a common issue facing Asian countries.

Lagarde also said that Japan has more room for improvement in child care, reducing working hours and equal pay for work of equal value.