The United Nations high commissioner for human rights Michelle Bachelet has serious concerns about Australia's migration and asylum policies.

Key points: Ms Bachelet said her concerns include Australia's offshore processing and prolonged mandatory detention of refugees and asylum seekers

Ms Bachelet said her concerns include Australia's offshore processing and prolonged mandatory detention of refugees and asylum seekers She said she feared Australia's "public narrative" surrounding the policies could become weaponised by misinformation and racist attitudes

She said she feared Australia's "public narrative" surrounding the policies could become weaponised by misinformation and racist attitudes During the election campaign Scott Morrison promised to cap the number of migrants coming to Australia each year

During a Whitlam Institute Oration speech in Sydney on Wednesday, Ms Bachelet said the concerns included Australia's "so-called offshore processing regime and prolonged mandatory detention of refugees and asylum seekers".

Ms Bachelet also criticised the "public narrative in Australia" that surrounds the policies.

"Which I fear has become weaponised by misinformation and discriminatory — and even racist — attitudes, including with respect to Islam," Ms Bachelet said.

"Targeting migrants as convenient scapegoats for a range of society's troubles is a practice that is certainly not limited to Australia.

"Around the world we see some politicians and would-be opinion leaders who are only too eager to demonise some of society's most vulnerable and marginalised people for political gain."

During the election campaign, Prime Minister Scott Morrison pledged to freeze the number of humanitarian visas during the next term of government if the Coalition won.

When he announced the policy, Mr Morrison promised to cap the number of migrants coming to Australia each year as refugees at 18,750, and unveiled a suite of measures outlining precisely who would be allowed to stay.

Who is Michelle Bachelet? Ms Bachelet fled Pinochet's dictatorship for Australia before becoming Chile's first female president — twice. Read more Read more

Ms Bachelet urged compassion and humanity from authorities managing the issue.

"Desperate human beings seeking safety and dignity are victims, not criminals," she said.

"They are people just like us, tired and in need, and they are moving, many of them because they have no other choice.

"It seems to me very unfortunate that Australia, a country of migrants, has opted out of this important global discussion to find cooperative solutions.

"If we refuse dialogue, inclusion, respect and justice, we are in effect enabling injustice, cruelty, grievance and tensions that may fuel greater conflicts."

Ms Bachelet then spoke of the dissatisfaction people worldwide currently had with democracy.

She warned, pointing to the Extinction Rebellion demonstrations happening in 60 cities around the world, people would only continue to disengage if their participation was not met with "responsive and responsible policies".

"Policymakers need to listen to their demands," she said.

"Leaders — not just political leaders, but social and business leaders too — can and should encourage greater participation and involvement by young people, whose lives will be shaped by the issues that are coming to the fore right now.

"Rather than fuelling cynicism about the value of participation, they could and should be encouraging people to advocate policies that align with our most important personal convictions and ideals."

Bachelet responds to PM's swipe at UN

Ms Bachelet appeared to use part of her speech to respond to Mr Morrison's veiled swipe at the United Nations last week.

Mr Morrison used an important foreign policy lecture to urge against a "new variant" of what he called "negative globalism", saying he did not want to see organisations like the UN getting involved in the governance of independent nations.

Ms Bachelet said there was "rarely a serious gap between the interest of humanity, and the national interest of [her] country".

"If a policy seems in the short term to advance a narrow interest, but hurts the future of humanity, that policy is surely counter-productive," she said.

"We sometimes hear human rights being dismissed as supposedly "globalist" — as opposed to the patriotic interest of a sovereign government.

"But how can any state's interests be advanced by policies that damage the wellbeing of all humanity?"