O'Brien on deterring Russian meddling: "There’s almost nothing left to sanction"

White House national security adviser Robert O'Brien on Sunday defended President Trump's track record on deterring Russian interference in the U.S. election, telling NBC's "Meet the Press": "We've put so many sanctions on Russia there's almost nothing left to sanction."

Why it matters: A top counterintelligence official revealed in a statement Aug. 7 that the Russian government is "using a range of measures" to "denigrate" Joe Biden ahead of the election, while China and Iran would prefer that Trump is defeated.

Key exchange:

O'BRIEN: "We want all of them to stay out of the election and what we've done to make sure that happens is we've spent millions and millions of dollars hardening election infrastructure, working with 50 secretaries of state on cybersecurity, and we've also sent very strong messages to all these countries. With respect to Russia, we put so many sanctions on Russia there's almost nothing left to sanction."

CHUCK TODD: "So it's not working. "

O'BRIEN: "Look, these are foreign powers that are adverse to the United States. We are in a period of great power competition and look, Russia and China are on the other side. But what we've done is we've pushed back, unlike the last administration."

What to watch: O'Brien denied that President Trump has asked Russian President Vladimir Putin for a meeting in the U.S., but said that "at some time we'd love to have Putin come here hopefully to sign a terrific arms control deal that protects Americans and protects Russians."