China's economy will exceed 170 trillion yuan ($23.87 trillion) by 2030, Premier Li Keqiang said, quoted by "Reuters".
He pointed out that this represents a major market opportunity for the world as trade restrictions increase globally.
In his speech at the opening ceremony of the China International Import Expo in Shanghai, Li criticized tariffs and noted that China wants to reform the global economic and trade system to make it more reasonable and transparent, especially for developing countries.
Tariffs "seriously undermine international economic and trade rules, and also disrupt the normal operation of enterprises in different countries," he said, without mentioning the United States.
"In five years, China's economy is expected to exceed 170 trillion yuan, making a new and important contribution to global economic growth," Li said.
China said its gross domestic product will exceed 140 trillion yuan this year, and the forecast through 2030 is in line with proposals for its upcoming five-year plan, which forecasts annual growth of 4.17 percent over the next five years.
The China International Import Expo was launched under President Xi Jinping in 2018 to promote China's stance on free trade and counter criticism of its trade surplus with many countries.
The expo, however, has its skeptics, as the country's trade surpluses with other markets only have increased in the years since.
Although China's supply of manufactured goods to the world has grown, its contribution to global demand has been smaller, with imports barely growing - economists say this is fueling trade tensions abroad and deflationary pressures at home.
Global trade has been severely disrupted this year by tariffs imposed by US President Donald Trump, plunging the US and China into a new trade war.
Last week, Xi Jinping and Donald Trump met in South Korea to reach a trade truce. The US has agreed to reduce some tariffs on Chinese goods and suspend some export controls, while China has agreed to end new export restrictions on rare earth minerals and magnets and resume purchases of US soybeans.
However, analysts believe this may be just a fragile truce in a trade war whose root causes have yet to be resolved.
In his speech, Li said China wants to increase its imports of high-quality products and repeatedly stressed that it is open to business and trade.
"Let enterprises from all over the world develop in China with more peace of mind, more comfort and more confidence," he urged.
China's trade surplus is expected to surpass last year's record of about $1 trillion as exporters compensate for a drop in US sales due to higher US tariffs by selling more to the rest of the world, often at a loss in pursuit of market share.
Exports to the United States fell by about 27% in September compared with the same month of the previous year, while shipments to the European Union, Southeast Asia and Africa increased by 14%, 16% and 56% respectively.
The Ministry of Commerce announced that more than 155 countries, regions and organizations plan to participate in this year's China International Import Expo. More than 4,100 foreign enterprises will participate, with US companies maintaining the largest exhibition area for the seventh consecutive year.