BEIJING, March 24 (Xinhua) -- Chinese Vice Premier Han Zheng said Sunday that opening up has become "a distinctive symbol of contemporary China," and the country will unswervingly open still wider to the outside world.

"China has pursued development with its door open and succeeded in transforming a closed and semi-closed economy into an all-round open economy," Han said at the opening ceremony of the China Development Forum 2019 in Beijing.

Opening up was key to China's economic growth in the past, and the high-quality development of China's economy in the future can only be achieved with greater openness, he added.