WASHINGTON — US Treasury Secretary Janet Yellen said the design and development of a digital dollar would likely take years if the US chose to create one, while outlining the various questions the Biden administration is weighing as it considers ways to make payments faster in the US.

As part of President Biden’s executive order on cryptocurrency, the administration is studying the possibility of issuing a central-bank digital currency, following up on efforts at the Federal Reserve. Other countries including China have created a central-bank digital currency, or CBDC, as they try to keep up with the rise of cryptocurrencies.