Indonesia's president, Joko Widodo, turned to the language of comic books to describe the threats the world faces today.

"Not since the great depression of the 1930s have trade wars erupted with the intensity that they have today. But rest assured, I and my fellow Avengers stand ready to defend Thanos from wiping out half of the population," he said in a plenary speech at the World Economic Forum on the Association of South East Asian Nations (ASEAN) on Wednesday.

"We must prevent trade wars from becoming the infinity war," he said, referring to the plot of a Marvel comic-turned-Hollywood blockbuster.

"You might be wondering – who is Thanos? Thanos is not any individual person. Sorry to disappoint you. Thanos is inside all of us. Thanos is the misguided belief that for us to succeed, the other must surrender, the misconception that the rise of some means the decline of others," he said.

The president used tongue-in-cheek language to make a serious point: economics is not a zero sum game of winners and losers. Countries can trade and prosper together, as many leaders from the region underlined.

"Infinity wars is not only about trade wars but about each and every one of us relearning the lesson of history that with creativity, energy, collaboration and partnership we shall enjoy abundance, we shall produce not an infinity war but infinite resources," Widodo said.

Hu Chunhua, Vice Premier of the People's Republic of China, had a similar message, without the superhero references.

"We need to uphold openness and mutual benefits. Self-isolation will lead nowhere," he said. "We must categorically reject protectionism and unilateralism."

China is currently retaliating to trade tariffs imposed by US President Donald Trump with levies of its own on goods including American soybeans.

But the vice premier said that China sought an open, inclusive global economy.

"China’s resolve to open its doors even wider will not change, we will pursue opening up at its own pace. This will offer opportunities for ASEAN countries and beyond."