Republican Sen. John McCain said in an interview aired Saturday on CNN he is "more worried about this country than I've been in my entire lifetime."
McCain laid much of the blame on the past eight years of President Barack Obama, to whom he lost the White House in 2008.
"We are seeing strains on the world order," McCain told "Axe Files" host David Axelrod. "We are seeing China, we're seeing 6 million refugees, 400,000 killed, the list goes on and on, a world in incredible turmoil."
Though he had his differences with then-candidate Donald Trump, and supported South Carolina Sen. Lindsey Graham in the GOP primaries, McCain said it is now his job to try to work with President Trump.
McCain said he feels Trump's advisers can move him when needed.
"I know that he has great respect for those that he appointed as his national security team, so I do believe he listens to them," he said.
But McCain said it shocked him when Trump said during the campaign that the United States lacked the moral standing to question human rights abuses by Russia.
"To state that there's some moral equivalency between an imperfect nation — that's the United States of America -- and Vladimir Putin is appalling," he said.