China needs to guarantee a "bottom line" of 6.5 percent annual economic growth for its 13th five-year-plan, a state newspaper quoted the director of the National Development and Reform Commission (NDRC) Department of Planning, Xu Lin as saying.

That would mark the lowest annual growth rate since 1990.

The comments by Xu, made on Feb. 14 at the "50 Forum Annual Meeting" - a gathering of Chinese economists - is also an acknowledgment that China is switching to a more sustainable pace of growth from the double-digit rates of the recent past.

If this year's GDP growth is 7 percent, then the "bottom line" for annual GDP growth in the 13th five-year-plan needs to be at least 6.5 percent, the China Securities Journal quoted Xu as saying.

China's economy grew at 7.4 percent in 2014, its slowest pace in 24 years, dragged down by cooling property prices, slowing inflation and deteriorating domestic and foreign demand.

Beijing is set to unveil China's 13th five-year-plan after the National People's Congress in March. The plan is an important document that outlines national priorities and sets targets for economic and social development.

The International Monetary Fund said last year that China should set a less ambitious growth target of 6.5-7 percent in 2015 and refrain from stimulus measures unless theeconomy threatens to slow sharply from that level.

China also needs to prioritize the systemic reform of property rights, taxation, banking, finance and rule of law, among other national priorities, Xu said.