BEIJING -- China's aging population and the deteriorating natural environment will constrain economic growth, Ma Jiantang, head of the National Bureau of Statistics said Saturday.

China's "demographic dividend" has decreased as the population is aging fast, and environmental problems will continue. Both factors will hamper the country's economic growth, Ma said at the China Development Forum held in Beijing.

Ma's remarks came after China lowered its GDP growth target in 2012 to a seven-year low of 7.5 percent last week to give more leeway to restructure its economy without fuelling inflation.

The country's ratio of labor force to the overall population dipped for the first time in 2011, Ma said.

Meanwhile, in contrast to limited natural resources per capita, China's energy and resource consumption were enormous, which has resulted in high costs to curb heavy pollution, he said.

The country must step up reforms and restructuring to secure steady and rapid economic growth, Ma concluded.