The US Treasury Secretary is to call Wednesday to reform the world's major economic institutions, saying the war in Ukraine proved the need for change in such organizations.

"We will... need to modernize our existing institutions -- the IMF and the multilateral development banks -- so that they are fit for the 21st century, where challenges and risks are increasingly global," Janet Yellen plans to say at a conference organized by the Atlantic Council think tank.

Yellen is scheduled to speak about her vision for the global economy in the context of the Ukraine conflict, a week before finance ministers and central bank governors go to Washington for the spring meetings of the International Monetary Fund and the World Bank.

"Some may say that now is not the right time to think big. Indeed, we are in the middle of Russia's war in Ukraine," Yellen is to say. "Yet, I see this as the right time to work to address the gaps in our international financial system that we are witnessing in real time."

The United States has imposed several rounds of economic and financial sanctions on Russia, including freezing assets and banning transactions of major Russian banks.

These measures should force the Kremlin "to choose between propping up its economy and funding the continuation of Putin's brutal war," Yellen will say.

In her speech, she also plans to denounce countries and companies that have not severed economic ties with Russia -- although without specifying them by name.

China and India, in particular, have remained partners with Moscow.

These countries may see "an opportunity to gain by preserving their relationship with Russia and backfilling the void left by others. Such motivations are short-sighted," Yellen will warn.

Beyond the situation in Ukraine, next week's meetings will also focus on vaccine deliveries, the fight against global warming and support for low-income countries, Yellen plans to say.