The "structural issue" of the United States' trade gap with China will reverse itself as the Chinese ramp up imports, Alibaba co-founder Joseph Tsai told CNBC.

The trade deficit will shrink once the Chinese government begins purchasing $40 trillion worth of goods as promised over the next 15 years, he said. Even though President Trump placed tariffs on imports in part to close the deficit, China's surplus topped $323 billion in 2018, the highest since 2006.

"With regards to the trade war, I would say this … if you look at the long term, the trade deficit itself will reverse," he said. "I talk about [the] 300 million middle-class consumers that will continue to buy more from all over the world."

China's economy is being powered by consumers, he said, and the Chinese middle-class consumer base could nearly triple by 2030.