Treasury Secretary Janet L. Yellen urged her counterparts at a summit in India to condemn Russia’s actions, and she defended the cost of supplying aid to Kyiv. 

A year after Russia’s invasion of Ukraine, the war is deepening the division among the world’s major economies, threatening fragile recoveries by disrupting food and energy supply chains and distracting from plans to combat poverty and restructure debt in poor countries.

Those fissures were evident this past week as top economic policymakers from the Group of 20 nations gathered for two days at a resort in Bengaluru, a city in southern India, where efforts to demonstrate unity were overshadowed by flaring tensions over Russia. During the summit, Western nations imposed a barrage of new sanctions on Moscow and unveiled more economic support for Ukraine, while developing countries like India, which have been reaping the benefits of cheap Russian oil, resisted expressing criticism.

The differing views left officials struggling to cobble together the traditional joint statement, or communiqué, on Saturday, forcing senior representatives from the Group of 7 nations, the world’s most advanced economies, to try to convince reluctant counterparts that defending Ukraine was worth the cost.

“Ukraine is fighting not only for their country, but for the preservation of democracy and peaceful conditions in Europe,” Treasury Secretary Janet L. Yellen said on Saturday in an interview, explaining the case that she had made to the more reluctant countries. “It’s an assault on democracy and on territorial integrity that should concern all of us,” she added.

The summit took place at a pivotal moment for the global economy. The International Monetary Fund last month upgraded its global output projections but warned that Russia’s war in Ukraine continued to cast a cloud of uncertainty. The fund also noted that increasing “fragmentation” in the world could be a drag on growth in the future.

Ms. Yellen was among the most forceful critics of Russia during the two-day meeting. At one point, she directly confronted senior Russian officials in a private session and called them “complicit” in the Kremlin’s atrocities.