BEIJING — A member of the top Chinese decision-making body called Sunday for sweeping economic changes, including a reduction in state control, as China’s economy struggled with surplus production capacity and risks to the financial system.

Deputy Prime Minister Zhang Gaoli, a member of the Politburo Standing Committee, warned that failure to make changes would consign the economy to years of low-quality growth.

“There are increasing downward economic pressures, and the problem of excess capacity is worsening,” Mr. Zhang said. “Objectively speaking, there are potential risks in the financial area.”

China’s economy, worth 52 trillion renminbi, or $8.4 trillion, fought its worst slowdown in 13 years last year after weak exports and interest rate increases from the year before dragged annual growth down to 7.8 percent — impressive by world standards but the grimmest for China since 1999.