NUSA DUA, Indonesia - U.S. Treasury Secretary Janet Yellen on Friday urged Group of 20 major economies to take urgent action to address a short-term food insecurity crisis exacerbated by Russia's war in Ukraine, and avoid market-distorting export restrictions and stockpiling.

Yellen, speaking at a meeting of G20 finance officials in Indonesia, said countries should target fiscal support measures to help those most in need, rather than adopting costly and regressive blanket subsidies.

She also called on G20 members to boost their spending to address existing food security challenges linked to conflict, climate change, and economic shocks from the COVID-19 pandemic that had grown worse due to war-related increases in food, fertilizer and fuel prices.

Russian President Vladimir Putin was "using food as a weapon of war," she said, citing "the destruction of agricultural facilities, theft of grain and farm equipment, and the effective blockade of Black Sea ports."

Yellen said poor households in the poorest countries were the most directly affected, setting back development and undermining efforts to eradicate poverty.

"We must take action to address the short-term food insecurity crisis and, equally importantly, the longer-term drivers of food insecurity, including the nexus with climate change," she said. "The speed and wisdom of our decisions now will make the difference on whether we get the current crisis under control."

Yellen said G20 countries should leverage the existing food security and agriculture architecture, and insist that the multilateral development banks, the Rome-based food agencies and the Global Agriculture and Food Security Program (GAFSP) and others respond more urgently.

"We don’t need new institutions. We need robust coordination, knowledge sharing, research and development, financing, and action," she said, lauding creation of the Global Alliance for Food Security as a helpful move.

Washington last month said it would commit a further $2.76 billion to tackling food insecurity, on top of $2.8 billion already provided since Russia’s invasion of Ukraine on Feb. 27.

The United States was also providing funds to an initiative launched by the European Bank for Reconstruction and Development, and would be contributing to the African Development Bank’s African Emergency Food Production Facility and other initiatives, she said.

(Reporting by Andrea Shalal Editing by Ed Davies)