" I absolutely did not use the term 'heads up.' There was nothing casual about this," Yates said in an interview with CNN's Anderson Cooper, which aired Tuesday night.
Yates, who was fired by Trump in January, said she called White House Counsel Don McGahn earlier that month to warn him that Flynn was "compromised with respect to the Russians." Flynn was later fired for misleading Vice President Mike Pence about the content of his conversations with Russian Ambassador to the U.S. Sergey Kislyak.
In an interview last week, Trump said it " did not sound like an emergency" when McGahn relayed Yates' message to him. White House Press Secretary Sean Spicer also described Yates' warning as a "heads up."
"I don't know if I used the word 'emergency," Yates told CNN. "But when you call the White House counsel and say you have got to meet with them that day about something you can't talk about on the phone, and you tell them that their national security adviser may be able to be blackmailed by the Russians, and that you're giving them this information so that they'll take action, I'm not sure how much more of a siren you have to sound."