Australia’s detention of a 17-year-old Kiwi in an adult deportation facility ignores United Nations agreements, New Zealand’s acting prime minister says.

Foreign Minister Winston Peters – standing in for Jacinda Ardern, who is on maternity leave – has said the issue has been raised with the Australian government.

The teen has been held at the Melbourne Immigration Transit Accommodation facility since March, awaiting a deportation hearing this month, reportedly over non-violent offending.

“We are joint signatories, along with many other countries, to UN conventions where children are concerned,” Mr Peters said on Tuesday.

“I’m just reminding the Australians ‘you’re a signatory, live up to it’.”

He said he would discuss the issue with counterpart Julie Bishop at a meeting in August.

“The Australians are very aware of what our views are on that and the expulsion of so many New Zealanders from Australia,” Mr Peters said.

“We’ve made it clear for a very long time we don’t like it … but Australia is a sovereign nation.”

The United Nations Convention on the Rights of the Child states “every child deprived of liberty shall be separated from adults unless it is considered in the child’s best interest not to do so”, except in exceptional circumstances.

More than 600 New Zealanders have had their visas cancelled in Australia since stricter deportation laws came into place in 2014.

Some have spent the bulk of their lives in Australia and have no connections to New Zealand.