National Security Adviser Robert O'Brien vowed to protect the 2020 U.S. election from foreign interference, whether they back President Donald Trump or challenger Joe Biden, saying any country that interferes risks "severe consequences."

"Whether it's China or Russia or Iran, we're not going to put up with it," O'Brien said on CBS on Sunday.

A report by U.S. intelligence agencies on Friday said Russia is working to see Trump win re-election while China and Iran would like to see him lose. Asked about the possibility of U.S. adversaries skewing the result, O'Brien said that the Trump administration will be evenhanded in ensuring a free and fair election.

He declined to say whether Trump told Russian President Vladimir Putin during a July 23 conversation to refrain from meddling in the U.S. election, saying he doesn't get involved in the president's conversations with foreign leaders. "But nevertheless, we continue to message the Russians," O'Brien said. "And President Trump continues the message to the Russians: Don't get involved in our elections. And by the way, that message is to the Chinese and that message is to Tehran as well. Don't do it because there will be severe consequences."

While O'Brien didn't spell out specific consequences, he cited previous economic and diplomatic sanctions the administration has imposed on Russia. "There's not a lot left we can do with the Russians" in terms of sanctions, he said.

Bloomberg News