Snowden himself tweeted out the NBC report, along with a claim that it represents "irrefutable evidence that I never cooperated with Russian intel. No country trades away spies, as the rest would fear they're next."

Finally: irrefutable evidence that I never cooperated with Russian intel. No country trades away spies, as the rest would fear they're next. https://t.co/YONqZ1gYqm — Edward Snowden (@Snowden) February 10, 2017

Interestingly, this claim comes at the same time CNN reports that for the first time, US investigators have verified "some" of the details in the 35-page dossier compiled by a former British intelligence agent, and released by Buzzfeed. The details verified don't relate to the more explosive details, but confirm that certain conversations mentioned in it did happen at the times listed.