Kurds have rallied in major cities in Australia calling for an end to Turkey's military action in Syria, as the death toll from the conflict rises.

Turkey has stepped up its military offensive launched during the week after US President Donald Trump announced the withdrawal of US troops from the Kurdish-majority region in north eastern Syria.

Warplanes and artillery have hit Kurdish militia targets in Syria, killing dozens of civilians and fighters and forced tens of thousands to flee.

SBS News

Protesters in Sydney, Melbourne, Adelaide and Brisbane carried Kurdish flags and chanted "shame Turkey" and "shame Donald Trump" with many accusing the US of betraying the Kurds after relying on their fighters to defeat IS.

In Sydney, Zirian Fatah said the time for words was over, urging the Australian government to propose a resolution to the United Nations to impose a no-fly zone for Turkey.

READ MORE Why the world needs to be watching what is happening to the Kurds in Syria right now

Mr Fatah, who is vice-president of the Kurdish Lobby Australia, said Mr Erdogan's actions would create a "terror corridor" which could directly affect the West.

"The reality is this doesn't only affect Kurdish people or Kurdistan. This is a worldwide problem."

SBS News

Continued military action in the region will result in the release of thousands of IS prisoners who had been under Kurdish control, allowing them to travel anywhere in the world, he said.

"I'd say to people not only in Sydney and Australia but people all around the world especially in the west...once Erdogan invades further in, these 10,000 IS detainees will be released and you never know where they will pop up.

"And please don't tell us we didn't tell you, because they will pop up in any corner and every corner of the world as IS has planned all along."

Australian Kurds and their supporters gather at the SA Parliament to protest against Turkey's offensive in Northern Syria @SBSNews pic.twitter.com/MGF08goWim — Jarni Blakkarly (@JarniBlakkarly) October 12, 2019

Scott Morrison says ignore 'other narratives'

After speaking to US Secretary of State Mike Pompeo on Saturday morning, Prime Minister Scott Morrison was putting the blame squarely on Turkey.

"They are the ones walking across borders for no other reason than that is what they seek to do for their own purposes, and Australia has condemned that.

"That is not something that we support and it has certainly been spoken against by many of our like-minded partners around the world."

AAP

Mr Morrison repeated Australia's call for restraint, particularly on the part of Turkey.

"At the same time, let's not indulge in any of these other narratives. I don't think they hold water at all."

Asked if he was referring to suggestions that US troop withdrawal gave Turkey the green light to invade the Kurdish-majority region, Mr Morrison said: "This is the unilateral action of Turkey. We want to deal with this. That is what we have to focus on."

US considers sanctions

Facing a backlash for appearing to greenlight Turkey's assault against Kurdish forces in Syria, President Donald Trump on Friday dialled up pressure on America's NATO ally by threatening crippling sanctions.

Treasury Secretary Steven Mnuchin said Trump had authorised - but not yet activated - "very significant new sanctions" to dissuade Turkey from further offensive military action.

EPA

Defence Secretary Mark Esper weighed in forcefully, saying Turkey risked destabilising the region and accusing President Recep Tayyip Erdogan of taking "impulsive action."

Mr Esper "strongly encouraged" Turkey to halt the offensive, warning of "serious consequences," adding that he and Joint Chiefs Chairman Mark Milley had spoken directly to their Turkish counterparts.

Mr Erdogan on Friday swiftly dismissed Mr Esper's call.

"Now there are threats coming from left and right, telling us to stop this," Mr Erdogan said. "We will not step back."

On Friday, the Pentagon confirmed that US troops near the northern Syrian border came under artillery fire from Turkish positions.

No US personnel were hurt, but Pentagon spokesman Navy Captain Brook DeWalt warned Ankara against "actions that could result in immediate defensive action."

The Syrian Observatory for Human Rights said Friday that the civilian death toll was 17 on the Syrian side, while 17 have also been killed in Turkey.

According to the Observatory, 54 fighters from the SDF have also been killed while Turkey has reported the deaths of four soldiers.

Additional reporting by AAP and AFP