In an interview with NBC’s Chuck Todd, Biden smiled when asked why the US has not acted a week after formally accusing the Russian government of trying to interfere with the 2016 election.

“We’re sending a message” to Russian President Vladimir Putin, Biden said. “We have the capacity to do it and the message will be sent. He’ll know it and it will be at the time of our choosing and under the circumstances that have the greatest impact on the capacity to do –to fundamentally alter the election. To do, it is not what they think. I’ll tell you what, to the extent that they do, we will be proportional in what we do.”

Asked whether the public will know when it happens, Biden responded: “I hope not.”