The G20 group of economic powers warned Friday that the world economy could worsen under the pressure of rising unrest, protectionism, and frail financial systems.

"The uncertainty and the risks facing global economy have increased, as some major economies have entered into general elections, the fallout of Brexit is uncertain, the vulnerabilities of the financial system are rising, (and) the expectation of geopolitical tensions are growing," said Lou Jiwei, China's finance minister and the current leader of the G20.