Around A$25 billion ($18.93 billion) will be added to the Australian economy in the next two decades through trade agreements with China, Prime Minister Malcolm Turnbull said on Sunday.

Australia is dedicated to implementing the bilateral free trade agreement with China and will continue to welcome Chinese investment, Turnbull said at the B20 Summit in Hangzhou.

"We've already gained many dividends from the FTA signed last year," he said.

The B20 provides a plat-form for international companies and chambers of commerce to participate in global economic governance, as well as economic and trade regulation, through meetings that collect the opinions of world business leaders and make recommendations to the G20 leaders.

Turnbull emphasized the importance of FTAs, especially for developing countries, as he said trade protectionism and isolationism will hinder trade flows and global investment. G20 trade ministers have said they are committed to ratifying a trade facilitation agreement by the end of this year.

Research by the Organizations for Economic Cooperation and Development shows full implementation of the agreement could cut trade costs by more than 10 percent for OECD countries and by 12.5 to 17.5 percent globally.

Ning Gaoning, chairman of the B20's trade and investment task force and chairman of Sinochem Group, said more ports, warehouses and logistics facilities needed to be built to stimulate global trade.

China and Australia signed an FTA in June last year. Under the deal, tariffs on 95 percent of Australian exports have been lifted, while obstacles will be removed to allow more Chinese businesses to invest in the country. Australian visa policies have also been relaxed for Chinese visitors.

China is already Australia's largest export market, with commodities, natural resources and agricultural products topping the list of exports.

The goods and services trade between China and Australia amounted to A$155.5 billion last year, growing 2 percent year-on-year, according to the China Council for the Promotion of International Trade.