China, which claims the island as its own, condemned the visit which comes after a period of sharply deteriorating relations between China and the United States.
There are more than 200 COVID-19 vaccine candidates in development around the world, including more than 20 in human clinical trials.
The WHO failed at its core mission of information sharing and transparency when member states do not act in good faith. This cannot ever happen again, U.S. Secretary of Health and Human Services Alex Azar said.
Nearly all 50 U.S. states have begun to allow some businesses to reopen and residents to move more freely, but only 14 states have met the federal government's guidelines for lifting restrictions.