Local and provincial authorities must continue to abide by China's current family planning policy until a new policy allowing all couples to have two children goes into effect after being ratified by legislators, the National Heath and Family Planning Commission said in an online statement issued on Sunday.

The authorities should not carry out the new policy "willfully", the statement said, responding to a claim made by one local official that the new policy took effect as soon as it was announced on Thursday.

"Those who are pregnant with a second child will not be punished as of today," Zhan Ming, deputy director of the provincial health and family planning commission in central Hunan province, was quoted as saying by Hunan Daily on Friday.

The Communist Party of China Central Committee announced the abolishment of the decades-old one-child policy on Thursday, in an attempt to balance population development and offset the burden posed by an aging population.

A final plan for the policy change is expected to be ratified by the annual session of China's top legislature in March.

The one-child policy was introduced in the late 1970s to curb China's surging population by limiting most urban couples to one child and most rural couples to two children, if the first child was a girl.

The policy was later eased to say that any parents could have a second child if they were both only children. That rule was further relaxed in November 2013 to its current form, which stipulates that couples are allowed to have two children if one of the parents is an only child.

Xinhua contributed to this story.