President Biden was "trying to be moderate" with his newly-announced COVID-19 vaccine rules, Dr. Anthony Fauci says. 

Fauci, Biden's chief medical adviser, spoke with CNN about Biden's speech Thursday announcing that the Labor Department will require businesses with more than 100 employees to require proof of vaccination or weekly negative COVID-19 test results. Additionally, all government workers will be required to be vaccinated. The president is "clearly frustrated" with Americans not getting vaccinated, Fauci told CNN, adding that he is "equally frustrated" himself. 

Fauci also defended the vaccine rules announced by Biden, which Republican governors have promised to challenge, arguing they're "moderate" because of the option for weekly testing. 

"I think the president is being somewhat moderate in his demand, if you want to call it that, in that there are some people who really don't want to get vaccinated, but they don't want to lose their job," Fauci said. "You've got to give them an off lane. … So it really is somewhat of a compromise there." 

Fauci suggested he would personally be in favor of not offering this "off lane," though, saying, "Myself, I would make it just vaccinate or not, but [Biden] was trying to be moderate in what his pronouncement was." This answer came in response to a question from CNN's Dr. Sanjay Gupta, who wondered, "Why not just do the vaccine mandate and not say that the testing can be sort of this off ramp?" 

Fauci also argued that Biden does have the authority to implement these rules, telling CNN he doesn't see "any issue" that would prevent them from going into effect.