He also believes Russian leader Vladimir Putin is a greater threat than the terrorist group ISIS.
“I have taken the practice of not reacting to what the president says but what the president does,” McCain told ABC TV.
He cited the US military response to the gassing of hundreds of civilians by the Bashar regime in Syria.
The senator believes Trump has the confidence of his national security team, and, most of the time, accepted their advice.
“Can I tell you that he does [that] all the time? No. Does it bother me? Yes, it bothers me,” he said.
McCain warned Russia was trying to influence elections around the world, even though he’d seen no evidence they succeeded.
“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.”
McCain also called for US allies to assist in challenging Chinese assertions of sovereignty in the South China Sea.
“So we may be asking our allies and friends to make a larger contribution once we have and it will be soon, once we have announced a strategy for victory,” he told The Australian.
McCain is also expected to underline the importance of Australia’s historic ties with the US during a major foreign policy speech in Sydney on Tuesday.
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