A refugee expert says young refugees and migrants who feel marginalised in Australian society are more likely to join gangs and turn to violence.

Speaking at a symposium on refugees, Tindaro Fallo from South Australia's Migrant Resource Centre says newcomers often withdraw when they feel unwelcome.

Mr Fallo says it is important refugees and migrants can develop a balanced identity, that incorporates their own heritage and also the Australian culture.

"I think that when young people feel marginalised, they don't feel they belong in either their own culture group or the host culture, they look to be with people that might also be marginalised," he said.

"So we look at the marginalised in the Australian host culture, they could be bikies, they could be drug users, they turn to those groups because they share similar experiences."

Mr Fallo says there needs to be a more collaborative approach between state and federal governments when dealing with new arrivals.

"I see people 10, 15 years later and I realise that in some ways, we've let them down," he said.

"We provide a lot of intense support in the early period, and then move on to the next lot of new arrivals, and of course problems don't emerge until people start to experience difficulties and stress."