US Republican senator John McCain has labelled Russian President Vladimir Putin "a premier and most important" threat to the world, moreso than ISIS.
Appearing on the ABC's 7.30, McCain called Russia's attempts to destroy "the very fundamental of democracy" by intervening in the US and French elections, "the far greatest challenge that we have".
"I think [Putin] is the premier and most important threat more so than ISIS," he began.
"I think ISIS can do terrible things, and I worry a lot about what is happening with the Muslim faith and I worry about a whole lot of things about it but it is the Russians who are trying -- who tried -- to destroy the very fundamental of democracy, and that is to change the outcome of an American election.
"I view the Russians as the far greatest challenge that we have."
McCain also discussed his views on the presidency of Donald Trump, saying he now doesn't react "to what the President says but what the President does."
The former Republican nominee, who ran against Barack Obama in the 2008 US election campaign, criticised the former President and suggested a Trump presidency is gaining credibility for the US because he acts as he promised to act, despite European leaders appearing nervous of his leadership.
"When I look at the world in 2009, when Barack Obama became President of the United States, and I look at the world today, it is dramatically changed and [that is] one of the major reasons for [the US] leading from behind," he said.
"The United States of America is supposed to lead. Do you know one of the reasons why President Trump was so warmly received by all of these Middle Eastern countries? Because at least they see some positive leadership.
"When Barack Obama said that they had crossed the red line with the use of chemical weapons and then didn't do anything about it, America lost credibility. I believe that if you're looking at the standard of what actually happens versus what is said, then I'll be glad to compare Donald Trump to Barack Obama, including the latest, when chemical weapons were used and we saw these dead children, at least we launched cruise missile strikes in retaliation.
"When America abandons its leadership then bad things happen and that vacuum is filled with evil influences. So I appreciate the European's viewpoint and their repudiation of Donald Trump"
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