Kono spoke in Paris on Thursday at a meeting of business leaders and government officials from OECD member nations.
Alluding to US-China trade friction, Kono said protectionist tendencies are creating tensions among countries.
He said the G20 summit will be held as the international community stands at a crossroads and confidence in the international order is wavering.
Kono said “our highest priority” is to support the liberal international order, including a free and fair trading system. He said the system has led to global prosperity since the end of World War Two.