As 50 million people in developing nations are on the brink of starvation, Australia is being urged to use its standing at the G20 to take action.
Prime Minister Anthony Albanese is attending the G20 summit in Bali along with leaders of other major economies.
Oxfam international inequality lead Anjela Taneja said Australia could be a leader in ensuring climate issues are addressed and fixing the "broken" food system.
"It is critical for all the G20 countries to come together and prioritise what people across the world need and deserve," she told AAP.
"We need to reject austerity and commit to reducing inequality."
Food and energy security were topics of the first session of the two-day summit.
Mr Albanese spoke about the need for countries to take action on climate change and manage growing debt faced by vulnerable economies.
He spruiked Australia's role as a major agricultural exporter and the need to promote trade to ensure long-term resilience in the food supply chain.
Ms Taneja said the biggest corporations in G20 nations are making record profits, while poor nations are crippled by the cost-of-living crisis.
"It's important the G20 doesn't end up being a talking shop, but results in tangible commitments that result in changing the lives of people around the world," she said.
A coalition of Australia's leading development and aid groups, Help Fight Famine, has marked the start of the summit with several recommendations to put a stop to widespread hunger.
Escalating conflict and extreme weather events caused by the changing climate are exacerbating the already dire malnutrition crisis.
Russia has been accused of using the crisis as a bargaining chip in its invasion of Ukraine, stopping export routes and driving up food and fertiliser prices.
Mr Albanese is being called on to commit $150 million to provide immediate relief to the hunger crisis in the Horn of Africa, where famine threatens 300,000 people.
The group also wants a $200 million annual commitment to address the root causes of hunger, such as investing in the global food strategy.
Save the Children CEO Mat Tinkler said Australia can be a champion for developing nations at the G20 by advocating for solutions to end hunger for all.
"The world's poorest and most vulnerable are malnourished and dying, yet there is capacity to feed everyone," he said.
"To achieve that we need the will and diplomacy of wealthier nations.
"The hunger crisis needs urgent funding now, but we also need to look at tackling the conditions that allow millions of people to starve."
The federal government is also being urged to significantly increase its climate finance commitment, as well as encourage other wealthy nations to protect food systems against climate change and conflict.
Oxfam Australia chief executive Lyn Morgain urged Australia to take concrete actions to help end the "catastrophic" food crisis unfolding around the world.
"Australia's unique diplomatic and scientific expertise can be a game-changer for the global food system," she said.
"It's time to play our part to bolster the world's food system against conflict and climate shocks."