Treasury Secretary Janet Yellen said the U.S. dollar is in no danger of losing its status as the world’s dominant reserve currency as a result of sanctions imposed against Russia over its invasion of Ukraine.

“I don’t think the dollar has any serious competition, and is not likely to for a long time,” Yellen told reporters in response to questions following a speech in Denver on Friday. 

Some commentators, including Credit Suisse Group AG interest-rate strategist Zoltan Pozsar, have warned sanctions that blocked Russia’s access to its foreign currency reserves could drive other countries away from the dollar.

“When you think about what makes the dollar a reserve currency, it’s that we have the deepest and most liquid capital markets of any country on earth,” Yellen said. “Treasury securities are safe, secure and immensely liquid. We have a well-functioning economic and financial system and the rule of law. There really is no other currency that can rival it as a reserve currency.”