US sanctions on Russia could threaten the dollar's hegemony, Treasury Secretary Janet Yellen told CNN.
The Chinese yuan is a competitor to the US dollar, amid Beijing's big ambitions for the currency.
"There is a risk when we use financial sanctions that are linked to the role of the dollar that over time it could undermine the hegemony of the dollar," Yellen told CNN's Fareed Zakaria in an interview.
Of course, it does create a desire on the part of China, of Russia, of Iran to find an alternative," Yelled said.
In January, the US dollar dominated global trade, accounting for about 85% of trade finance, according to a February report from global payments system Swift.