Dr. Anthony Fauci returned to the White House briefing room Thursday to provide an update on the country's COVID-19 response. He also made it clear that working for Biden is a lot different than working for Trump.

The infectious disease expert, who was sidelined by Trump toward the end of 2020, discussed key points of Joe Biden's strategy to combat the ongoing pandemic. Fauci touched on the country's renewed support for the World Health Organization, the plan to reopen schools and businesses, as well as the effort to increase vaccine distribution. But some of the most-talked about portions of his briefing occured when Fauci was asked about the differences between working with the Trump and Biden teams.

"One of the new things in this [Biden] administration is if you don't know the answer, don't guess," he said with a slight laugh. "Just say you don't know the answer."

Fauci also suggested that unlike the Trump administration, Biden's team will make decisions based on science and evidence, and will not play the blame game if and when mistakes occur. 

"Well, I can tell you my impression of what's going on right now ... one of the things that was very clear as recently as about 15 minutes ago—when I was with the president—is that one of things that we're going to do is to be completely transparent, open, and honest," he said. "If things go wrong, not point fingers, but correct them, and make everything we do based on science and evidence."

But he wasn't done. A reporter went on to ask Fauci if he felt "less constrained" under a Biden White House, and pointed out that Fauci appeared to make several jokes when comparing the previous administration to the new one. But Fauci made one thing very clear: He wasn't joking.

"You said I was joking about it. I was very serious about it. I wasn't joking," Fauci responded. "... It is very clear that there were things that were said—be it regarding things like hydroxychloroquine and other things like that—that really was uncomfortable because they were not based on scientific fact. I can tell you I take no pleasure, at all, in being a situation of contradicting the president.

Fauci went on to say that he now feels comfortable relaying important information to the country without fear of repercussions.

"The idea that you can get up here and talk about what you know, what the evidence, what the science is ... it is somewhat of a liberating feeling," he said.

Fauci made similar comments earlier this week, as Trump approached his final days in office. He told the Harvard Business Review that working with Trump was "somewhat awkward," as he would sometimes have to contradict what the former president said.