Donald Trump is an "American patriot", not a traitor to his country, Prime Minister Malcolm Turnbull says.
A number of American media outlets have accused the US president of treason following his meeting with Russian leader Vladimir Putin, in which Mr Trump said he trusted his Russian counterpart ahead of his own intelligence services.
Senior members of Mr Trump's Republican party have also rebuked him over his refusal to call out Mr Putin for interfering in US elections.
Asked on the Miranda Live program on Tuesday whether Mr Trump was a traitor, Mr Turnbull said: "Of course not. Donald Trump is an American patriot. His job is in representing his country and he is doing that to the best of his ability."
However, the prime minister said he found the evidence for Russian interference in the US elections "very compelling".
However, Mr Turnbull said he agreed with Mr Putin when he said "you shouldn't trust anybody".
"I certainly don't trust President Putin when he said he wasn't responsible for the shooting down of MH17, which was four years ago today."
The prime minister said he was working to protect Australia's democracy from foreign interference with new laws.