Yellen raised the issue during a conversation with Spanish Economy Minister Nadia Calviño, who heads the International Monetary Fund's steering committee, ahead of next week's spring meetings of the IMF and World Bank.
Yellen and Calvino discussed the upcoming meetings, recent developments in the global economy and financial system, and the need to continue support for low-income and vulnerable countries, Treasury said.
(Reporting by Andrea Shalal; Editing by Leslie Adler)
