Five hundred people took part in the rally starting outside the ABC's studios in Ultimo, with more driving alongside the protest in their cars, in keeping with NSW coronavirus restrictions.

Protesters called on the Australian government to "end their silence" on attacks by Azerbaijani and Turkish forces against the ethnic Armenians of Nagorno-Karabakh - a landlocked region between Turkey and Azerbaijan.

The region, which Armenians have self-declared as the republic of Artsakh - is legally recognised as part of Azerbaijan though is has been home to Armenians for thousands of years.

Armenian-Australians have been protesting across Australia in recent weeks since fighting broke out on September 27.

They want Prime Minister Scott Morrison to condemn Turkey and Azerbaijan, as has French president Emmanuel Macron.

Protest organiser Haig Kayserian told AAP on Saturday that Armenia-Australians were in state of extreme anguish.

"We're not sleeping. We're up all night trying to find out what's going on," he said.

Mr Kayserian has lost three friends in recent violence and said his fellow Armenian-Australians knew people who had been killed or were in danger.

The Sydney protest came as fresh clashes broke out a day after talks in Washington to try to end the deadliest fighting in the mountain enclave in decades.

Australian Associated Press