Demonstrations erupted across China in the past week over the country's strict COVID-19 policies.
Dr. Anthony Fauci said on NBC's "Meet the Press" that China's approach has been "rather draconian."
On CNN's "The Lead with Jake Tapper," Fauci said lockdowns should be temporary.
The nation's top infectious disease expert criticized China's "zero-COVID" policy as demonstrations erupted in the country, from Shanghai to Beijing, in the past few days.
Dr. Anthony Fauci, who is stepping down as President Joe Biden's top medical advisor and as director of the National Institute of Allergy and Infectious Diseases by the end of this year, said in multiple interviews that China's strict lockdown measures appeared to lack an end-game strategy.
"Their approach has been very, very severe and rather draconian in the kinds of shutdowns without a seeming purpose," Fauci said in an interview on Sunday with NBC's "Meet the Press" host Chuck Todd.
On CNN's "The Lead with Jake Tapper," Fauci reiterated on Monday that China needs to communicate a clear reason to the population for having lockdowns.
"If the purpose is, "Let's get all the people vaccinated, particularly the elderly," then okay, for a temporary period of time to do that," he said. "But they have very, very strict type of a lockdown."
Part of China's so-called "zero-COVID" strategy is to completely eradicate infection cases in areas where even a small number of coronavirus cases are found by implementing stringent lockdowns. This could mean severe restrictions on movement within neighborhoods or cities.
When Tapper asked about China's defense of its policies, saying that it was to reduce the spread of coronavirus, Fauci said that, once infection cases are reduced, there have to be tools in place to prevent another spread, pointing to vaccines.
"When you're talking about shutting things down, it should always be a temporary phenomenon, not a long-range strategy," he said. "You should do it with a purpose in mind to allow you to open. And the best purpose is, while you're shutting down, get as many people vaccinated as you possibly can with a good vaccine."
Fauci also suggested that China has the option to seek vaccines available in the US, such as Pfizer, but refuses to use them.
"As far as I know, it is available," Fauci told Tapper."I think it might be the other side not wanting to utilize those vaccines. I don't think there's any lack of availability, but I can't say for sure."