A decision to this effect, issued April 28 by Prime Minister Nguyen Xuan Phuc, aims to maintain a replacement total fertility rate (TFR) between 2 and 2.2 children for each woman in her reproductive life, increasing it in areas where it is currently low and vice versa.

The decision calls for people to marry before they are 30 and bear children early. Women should have their second child before 35, it advises.

Localities where fertility rates are 2.2 or below need to educate people on the benefits of having two children and the disadvantages of marrying and bearing too few children, too late, as well as their impacts on socio-economic development.

Localities should also encourage and support couples in having two children, expand worker-friendly services like babysitting, milk banks and family medicine. The decision says construction of babysitting facilities and kindergartens, especially in urban and industrial areas, should be paid particular attention.

Couples who have two children would benefit from several incentives including support in renting or buying subsidized housing and priority admission for children in public schools.

Vietnam's population hit 96.2 million last year, which is third in Southeast Asia and 15th globally, according to the Central General Census and Housing Steering Committee.

The country however reached a turning point in 2015 when it started to become one of the countries with the fastest aging populations in the world, the Ministry of Labor, Invalids and Social Affairs said in a 2016 report.

Several localities have seen birth rates fall way below the ideal replacement fertility rate of two children per woman. For example, women in Ho Chi Minh City are having around 1.36 children on average, while corresponding rates in the southern provinces of Dong Thap, Hau Giang and Ba Ria-Vung Tau are 1.34, 1.53 and 1.37.

Low fertility rates would result in a quickly aging population, straining social welfare systems, including pensions, health insurance and social security, experts have warned.