Students at a school in Ho Chi Minh City. Photo: Dao Ngoc Thach seeking to remove the restriction, warning that the country's birth rate has become alarmingly low. Years after Vietnam first asked families to have no more than two children, policymakers are now

The General Office for Population Family Planning, under the Ministry of Health, made the proposal in its latest draft for the population bill, which is going to be discussed during the ongoing month-long sitting of the National Assembly, news website VnExpress reported on Monday.

Under the proposal, Vietnamese parents will have a right to decide how many children they want and the interval between births.

Nguyen Van Tan, deputy chief of the office, was quoted as saying that the two-child policy needs to be loosened gradually so the country's birth rate can return to the desired replacement level of 2.1 children per woman.

For at least five decades, Vietnam's national family planning policy has encouraged parents to have only one or two children. It is believed to be a reaction to the 1970's rate of 6.8 births per woman.

The government reportedly eased the restriction in 2003, prompting many women to give birth to more than two children again. It then brought the policy back in 2009.

Since then, Vietnam's total fertility rate has been always lower than the replacement rate, although it differs from regions and provinces.

For instance, it has been 1.68 in Ho Chi Minh City over the last six years, and 1.7 in the southern province of Ca Mau.

Meanwhile, in some central provinces like Ha Tinh and Quang Tri, it has been 2.95 and 2.75, respectively.

If Vietnam continues to control births, the national rate will become too low to be able to recover, a problem already faced by some Asian countries including Japan and South Korea, where governments have failed to bring their birth rates up.

When the restriction is removed, Vietnam's population will possibly increase, but it will happen in the short term only, according to Tan.

If the fertility rate is kept at 2.1, the population will be 115-120 million by 2049, he said.

Vietnam's population was 90.5 million as of last year.