Trump

or

Mr. Burns?

You know what uranium is, right? This thing called nuclear weapons like lots of things are done with uranium including some bad things.

Who said it?

You're right! Donald Trump said this. Nope, sorry. Donald Trump said this.

This is from Donald Trump’s Feb 16, 2017 press conference at the White House. Watch below (~ 52m mark) or stop by the failing New York Times for a transcript.