The unusual clash occurred during violent protests over the death of a young woman in "morality police" custody because her scarf was allegedly loose.
Marina Ovsyannikova said the war in Ukraine "was the point of no return," and she felt she had to act.
The veteran journalist revealed she will undergo her final chemotherapy session to treat her ovarian cancer.
The 63-year-old CNN journalist told viewers that she recently had "successful major surgery" to remove the cancer and is "confident" about her recovery.
The former Fox News anchor accused the network's opinion division of propagating lies and explained why he stayed there so long.
Thunberg added, however, that world leaders needed to stop making nebulous net-zero promises and start reducing carbon emissions immediately.
The Supreme Court justice showed "characteristic modesty" when the documentary co-directors asked her the question.
“This is not Hollywood. This is real life, and real lives are at risk,” Chief Art Acevedo told CNN’s Christiane Amanpour.
The White House aide would not say if she'll urge the president to tone down his remarks about immigrants following the El Paso shooting.
The House speaker said that just because others "want to accuse somebody of that doesn’t mean that we take that bait."