Anthony Fauci, the government's top infectious diseases expert, told CNN on Monday that the Trump campaign should stop airing an ad that uses comments he made without his permission and out of context.

Why it matters: Fauci describes himself as apolitical and says he has never endorsed a political candidate in five decades of public service.

Context: A Trump campaign ad released on Saturday features a clip of Fauci saying, "I can't imagine that ... anybody could be doing any more." The clip appears edited to seem like Fauci is talking about President Trump. Fauci told CNN Sunday he made the comments months ago and was speaking broadly about federal health officials.

What they're saying: When anchor Jake Tapper asked how Fauci would react if the campaign made another ad that featured him, Fauci responded, "That would be terrible. I mean that would be outrageous if they do that."

• "In fact, that might actually come back to backfire on them. I hope they don't do that because that would be kind of playing a game that we don't want to play."
• Trump campaign spokesperson Tim Murtaugh defended the ad in a statement on Monday, saying that “these are Dr. Fauci’s own words."
• "The video is from a nationally broadcast television interview in which Dr. Fauci was praising the work of the Trump administration. The words spoken are accurate, and directly from Dr. Fauci’s mouth," Murtaugh added.

The big picture: Asked about President Trump's decision to continue having large campaign events that don't require attendees to wear a mask or social distance, Fauci said holding political rallies "is asking for trouble" — especially as the U.S. heads toward a winter season that could bring even higher rates of infection.

• "We have seen that when you have situations of congregate settings where there are a lot of people without masks, the data speak for themselves. It happens. And now is even more so a worse time to do that," Fauci said.
• "Because when you look at what's going on in the United States, it's really very troublesome. A number of states right now are having increases in test positivity. States above the Sun Belt, states in the Sun Belt. If you look at the map with the color coding of cases and states that are going up, you see states in the Northwest and the Midwest. It’s going in the wrong direction right now."
• "We're entering into the cool months of the fall and ultimately the cold months of winter. That's just a recipe of a real problem if we don't get things under control before we get into that seasonal challenge."

Go deeper: The onset of winter will make the coronavirus pandemic even worse