China's stock market rout isn't a reflection of the health of the world's second-largest economy, and efforts to stem a $5 trillion slide in equities fall within the "boundaries of reasonableness," the nation's top diplomat said in an interview.

The Shanghai Composite Index has tumbled about 40 percent since its June high, upending global markets and fueling fears of deepening weakness in the $10 trillion economy.

Those concerns are overblown, and China's "handsome" growth rate of about 7 percent will remain an engine for global expansion, said Yang Jiechi, one of five state councilors.