Mainland authorities will launch pilot projects in more than 20 cities to create a "new-era" marriage and childbearing culture, in the latest move to boost the country's birth rate.

The Global Times newspaper reported that the nation's Family Planning Association – which implements the government's population and fertility measures – will launch the projects to encourage women to marry and have children.

Promoting marriage, having children at so-called appropriate ages, encouraging parents to share child-rearing responsibilities, and curbing high "bride prices" and other outdated customs are the focus of the projects, the Times said.

Cities taking part in the pilot include the manufacturing hub Guangzhou and Handan in Hebei province. The association already launched projects in 20 cities, including Beijing last year.

"These pilot regions are expected to take innovative and proactive measures to … contribute to advancing Chinese modernisation with the support from the high-quality development of the population," said a vice president of the association, Yao Ying.

Demographer He Yafu also told the Times that "society needs to guide young people more on the concept of marriage and childbirth”.

The projects come amid a flurry of measures provinces are rolling out to spur people to have children, including tax incentives, housing subsidies, and free or subsidised education for having a third child.

China implemented a one-child policy from 1980 until 2015. The limit has since been raised to three children.

Concerned about the first population drop in six decades and rapid ageing, the government's political advisers proposed in March that single and unmarried women should have access to egg freezing and IVF treatment, among other services to boost the country's fertility rate.

Many women have been put off from having more children or any at all due to the expense of childcare and having to stop their careers.

Meanwhile, civil affairs agencies in several cities announced that they will accept marriage registrations on May 20.

May 20 is one of the dates on which Chinese couples prefer to register their marriages, as "520" is pronounced similarly to "I love you" in Chinese. (Additional reporting by Reuters)