China's top health authority said on Thursday that it will support efforts by the country's northeastern region to fend off challenges posed by low birthrates and the dwindling population by experimenting in fully relaxing the family planning policy.

The National Health Commission said that Northeast China－encompassing Heilongjiang, Jilin and Liaoning provinces－can put forward trial plans to encourage local families to have more than two children, after extensive research and analysis.

Expert research will focus on the policy's effects on local economic development, social stability, resource and environmental strategy and the public services sector, the commission said.

The region also needs to "gauge changes in local population following the policy shift, work on other supportive policies and appraise related societal risks", it added.

The comments were released on the commission's website in response to a proposal from a deputy to the National People's Congress, China's top legislative body.

The proposal suggested that the northeastern area be the first in the country to further loosen family planning rules, in a bid to halt the population decline.

China introduced a universal second-child policy that allows all families to have two children in 2016. However, the number of new births per year has remained stagnant, fueling concerns about a rapidly aging workforce.

The situation is most pronounced in the three northeastern provinces, which have recorded some of the lowest annual fertility rates, contributing to a drop in their overall population in recent years.

In 2019, the number of permanent residents in Northeast China went down by 427,000 from the previous year to about 108 million, data from the provincial governments shows. The population data for 2020 has not been released.

The commission said the region's population decline has been caused by a series of factors related to its regional economic model, industrial structure and social policies.

"For instance, as local resources have dried up and China is upgrading its industrial development, a large number of young people there are unable to find satisfactory local jobs and have moved to areas where economic growth is better and salaries are higher," it said.

The policy relaxation has so far failed to boost local families' willingness to have more children.

As a result, the commission said changing family planning policies are expected to have a limited impact on fertility decisions.

"Economic burdens, a lack of nursery care and the career development of females have become significant factors in swaying birthrates in the region," it said.

"In order to raise fertility levels, it is crucial to focus on the public's demands, resolve weaknesses in basic public services and address practical concerns on giving birth and rearing children," it added.

Lu Jiehua, a population studies professor at Peking University, told Beijing Daily that it would be "very difficult" to reverse the downward population trend in Northeast China. Loosening family planning rules is likely to yield limited outcomes, but the move will nevertheless set an example to the rest of the country.