About 2 million Chinese couples had applied to have a second child by the end of 2015, China's family planning authority said on Thursday.

"It is generally in line with what we expected," Zhai Zhenwu, chairman of the standing council of the China Population Association under the National Health and Family Planning Commission (NHFPC), told the Global Times.

According to Zhai, the total number of couples who apply to have a second child is expected to reach around 5 million over the next few years. He noted that the new two-child policy will help address the country's unbalanced sex ratio at birth.

National authorities have estimated that 2 million more infants will be born each year as a result of the relaxed family planning policy, and 80 percent of them will be born in cities, according to the Xinhua News Agency.

However, Huang Wenzheng, an expert on demographics, told the Global Times that the figure is far below what authorities have projected.

Huang noted that National Bureau of Statistics data shows that the country's newborn population dropped by 320,000 from 2014 to 16.55 million in 2015, instead of rising as family planning authorities expected.

China's top legislature eased the one-child policy at the end of 2013 by allowing couples to have a second child if one of the parents is an only child.

New legislation enacted at the end of 2015 completely abandoned the decades-old one-child policy, allowing all Chinese couples to have a second child.

According to a bulletin released by the NHFPC on Thursday, 89.2 percent of China's migrant workers has access to free family planning services.

The government spent 11.2 billion yuan ($1.7 billion) on supporting rural households' exercise of family planning last year - 1.46 billion yuan more than that in 2014 - and helped over 9 million individuals, the commission said.