There is a list. They'd rather the policy applies to that list, than the actual list items at the time of the writing, so that it can be updated.

> The most recent Countries of Particular Concern designations were made by the Secretary of State on November 30, 2022: Burma, People’s Republic of China, Cuba, Eritrea, Iran, the Democratic People’s Republic of Korea, Nicaragua, Pakistan, Russia, Saudi Arabia, Tajikistan, and Turkmenistan.

https://www.state.gov/countries-of-particular-concern-specia...