During a visit to Australia, Sen. John McCain told the ABC that he thinks Russia is a bigger threat to world security than ISIS.
"I think ISIS can do terrible things," McCain said. "But it's the Russians who tried to destroy the fundamental of democracy and that is to change the outcome of an American election."
He also categorized Vladimir Putin as the "premier and most important threat, more so than ISIS."
"We have done nothing since the election last November to respond to Vladimir Putin's attempt to change the outcome of our elections," McCain said. "So, way to go Vladimir. We haven't responded at all."
While the Republican senator said he sees no evidence that Russia succeeded in interfering with the U.S. elections, he finds it concerning that they tried and are still trying.
"They just tried to affect the outcome of the French election," he said. "So I view Vladimir Putin who has dismembered Ukraine, a sovereign nation, who is putting pressure on the Baltics I view the Russians as the far greatest challenge that we have."
In the sit-down interview with the Australian network, McCain also shared how he felt about Trump and national security.
"I am nervous from time to time," he said. "I do believe that the President has great confidence in the national security team. I do believe most of the time that he accepts their advice and counsel.
"Can I tell you that he does [that] all the time? No. Does it bother me? Yes, it bothers me," he added.
McCain was in Australia discussing Asia-Pacific security issues.