China's family planning policy is a changing process that will last a long time, not just "20 or 30 years", said a senior family planning official.

Wang Pei'an, deputy director of the National Health and Family Planning Commission made the remarks at the State Council Information Office on Monday.

"The essence of family planning has changed from curbing rapid population growth to striving for overall balanced demographic development," he said.

He referred to new measures, such as scraping the birth permit procedure and a maternity care model under changes to the 40-year-old family planning policy which now encourages couples to have two children.

The new law took effect on January 1.

He pointed out that overall guidance and management for childbearing would continue for a long period citing the nation's huge population base.

"Those who violate the rules by having more children will still be subject to the punishment of a social maintenance fee," he said.