Australian Ukrainians condemn Russia

She says her friends and family in Ukraine are trying not to panic, and believe they can get through the crisis with support from the international community.

"Some of my friends have heard rockets flying overhead. People are prepared with food and water in their homes but that's about it," she told AAP at the protest. 

"I feel absolutely helpless and there's nothing I can do but support the community except through mobilisation like here today asking for an intervention."

The group of 40 protesters chanted "stop Putin now" while holding Ukrainian flags and signs saying "sanctions are not enough".

Ms Bessonova says Australia should take stronger action than the sanctions announced against high profile Russians and financial institutions. 

"If we stop a couple of (Russian) officials flying to Australia, then that's not sanctions. They have to be stronger," Ms Bessonova said.

The Australian Federation of Ukrainian Organisations said Russia had chosen "a path of global isolation and aggression against the international rules-based order".

Mr Romaniw said resistance in Ukraine has grown since the 2014 annexation of Crimea and civil society remained strong. 

"I have spoken today to Ukrainians in Odessa, and they have told me that on the street, at every intersection, in every building and every house, Putin will find resistance," he said.

"We are ready to fight."

Victorian opposition leader Matthew Guy said Australian Ukrainians such as himself were "watching with horror at the invasion of a European democracy by the Putin dictatorship". 

"Sending love to my family in Kharkiv," he tweeted.

Meanwhile, counselling is being offered to almost 200 students from Ukraine and Russia studying at Australian universities.

Group of Eight chief executive Vicki Thomson said universities had acted quickly to identify and contact individual students, as well as relevant student clubs and societies, to offer support and check on their well-being.

Save the Children has warned that young people will bear the brunt of any conflict, with 40,000 children making up a large part of the 100,000 people who have been displaced in eastern Europe in recent days.

The organisation says any mass movement will put children in danger of hunger, cold and illness, as well as at risk of losing limbs and their lives from explosive devices, with eastern Ukraine being "one of the most mine-contaminated regions in the world".

"Children are terrified - they wonder if their homes will be shelled, their friends hurt, their security and sense of normalcy lost," Save the Children's eastern European director Irina Saghoyan said. 

"This is an appalling situation. But more fighting isn't inevitable. Leaders must step up, in the interests of the region's most vulnerable, its children."