"Public numbing and indifference" towards state abuses in Nazi Germany resembles that enabling Australia's immigration detention centres, a prominent psychiatrist says, also likening public complicity in the detention regime to the White Australia policy.

On Thursday Immigration Minister Peter Dutton, in Washington to discuss border protection at a Five Country ministerial meeting, repeated the Turnbull government's insistence that asylum seekers and refugees in Australia for medical care, and their families, would be returned to Nauru once their treatment has finished.

"The government has been consistent all along in relation to our strong stance to make sure we keep our borders secure," he said.