China's top economic planner said Tuesday the country's economic growth will remain in a proper range in the fourth quarter as government support policies to stimulate consumption and stabilize investment gradually filter through.

"I am confident we can achieve the annual growth target," Li Pumin, secretary-general of the National Development and Reform Commission, told a press conference.

He pointed to the slowdown in investment as major downward pressure on the economy. Earlier data showed China's urban fixed-asset investment grew 16.5 percent year on year in the first eight months of 2014, retreating 0.5 percentage points from the rate seen during the January-July period due to a continuing downturn in the real estate market.

To offset the impact, Li said China will step up investment in major water conservation projects, with the sum on ongoing projects estimated at around 600 billion yuan (97.6 billion U.S. dollars).

The official optimism came as some key economic indicators fell below market expectations in July and August, pointing to slowing momentum in the economy after a brief rebound in the second quarter, and fueling concerns that China may miss the annual growth target of around 7.5 percent.

Previously, the World Bank trimmed its 2014 growth forecast for China to 7.4 percent from 7.6 percent because it believes policies aimed at putting the economy on a more sustainable footing will sap growth. The International Monetary Fund left its forecast for China's growth this year unchanged at 7.4 percent.

In the first half of 2014, China's economy expanded 7.4 percent from a year earlier. The country is scheduled to release its third-quarter economic data on Oct. 21.