'Easy question' turns into tense back-and-forthpublished at 17:11 Greenwich Mean Time 29 January
Senator Elizabeth Warren, a Democrat, says she has an "easy question" for RFK Jr and asks if he will commit to not take money from big pharmaceutical companies.
Among several tense moments, RFK Jr appears to relish the question by smiling and replying: "Yes."
"I don't think any of them want to give me money," he says with a chuckle.
But it then turns into a fiery back-and-forth as they both speak over the top of each other.
Warren says RFK Jr profits from partnering with a company that recruits people to sue vaccine makers.
She asks if he agrees that he "won't take any compensation from any lawsuits against drug companies while you are secretary, and for four years afterwards".
"You're asking me to not sue drug companies? No, I'm not going to agree," he says.