Syrian President Bashar al-Assad has accused Australia of double standards for publicly criticising his government despite maintaining private dealings.

"This is the double standard of the West in general," he tells SBS in an interview airing on Friday night.

"They attack us politically and then they send officials to deal with us under the table... including your government."

Australia and other western nations are afraid of upsetting the US, Mr al-Assad says, and only repeat what the US wants them to say.

He's also hit back at criticisms from Prime Minister Malcolm Turnbull who has referred to him as a murderous tyrant and Opposition Leader Bill Shorten who has labelled him a butcher, declaring their comments "disconnected from reality".

"I'm fighting terrorists, our army is fighting terrorists, our government is against terrorists," he said.

"If you call fighting terrorism butchery, that's another issue."