Indonesian Finance Minister Sri Mulyani Indrawati opened the two-day meeting on Friday by urging fellow finance ministers, central bank chiefs and other leaders to find ways to "build bridges, not walls."

The consequences of failure, especially for less wealthy nations, would be "catastrophic," she said. "Millions and millions if not billions of people are depending on us."

Australian Treasurer Jim Chalmers is attending the summit, alongside Reserve Bank of Australia head Philip Lowe.

In their closed door meetings, the financial leaders are searching for ways to coordinate how they shepherd their economies through inflation that is running at 40-year highs, unsnarling supply chains and bottlenecks due to the coronavirus pandemic and fortifying financial systems against future risks.

US Treasury Secretary Janet Yellen called for the G20 to take action to fight food insecurity as millions go hungry due to soaring costs for food and other necessities.

It is crucial, she said, to avoid stockpiling and export bans, to provide financial help to the needy and to ensure all organisations, such as development banks and food agencies, do their part to alleviate hunger.

"The speed and wisdom of our decisions now will make the difference on whether we get the current crisis under control," Yellen said.

"The G20 must work together to tackle these challenges and protect vulnerable families from the threat of hunger today and tomorrow."

Indonesia is among the developing countries contending with shortages and rising prices of fuel and grain due to the war and it says the G20 has a responsibility to step up and ensure the rules-based global order remains relevant.

This week's meetings in Bali's heavily guarded Nusa Dua resort town follow a gathering there of foreign ministers earlier this month that failed to find common ground over Russia's war in Ukraine and its global impacts.

A G20 finance meeting in Washington, D.C. in April saw officials from the US, Britain, France, Canada and Ukraine walk out to protest the attendance of Russian envoys. That meeting ended without the release of a joint statement.

Caught in the middle as host, Indonesia has urged officials from all sides to overcome mistrust for the sake of a planet confronting multiple challenges from the coronavirus to climate change to Ukraine.

G20 financial meetings have the advantage of being less political in nature, Indrawati said. She said Indonesia, as host, has tried to act as an "honest broker," uniting a divided East and West, but there's no "playbook" for how to find agreement given the unprecedented tensions over the war.

Still, the G20 managed to bridge differences in coping with the 2008 global financial crisis and the pandemic, Indrawati said.

One key goal for Yellen and some other Western financial officials is gaining support for setting a price cap on Russian oil that might help bring energy costs under control and alleviate the decades-high inflation seen in many countries while also limiting Moscow's access to revenues to fund its war effort.

Yellen said on Thursday that no price had yet been determined for such a cap, but the level would have to be one "that clearly gives Russia an incentive to continue to produce, that would make production profitable for Russia."

Without a price cap, a European Union and probably a US ban on providing insurance and other financial services would take effect.

Yellen said she was "hopeful" that countries such as China and India that recently boosted imports of Russian crude oil, sold at steep discounts, would see it as being in their own self-interest to observe the price cap.

Australian Associated Press