Prime Minister John Key is being urged to step in following rioting on Australia's Christmas island detention centre.
Trouble broke out at the centre yesterday after the death of an asylum seeker who had escaped. The facility houses both asylum seekers and New Zealanders awaiting deportation.
Mr Key raised his concerns about the detention of New Zealanders when Australian Prime Minister Malcolm Turnbull visited this country in October. At that time, Mr Turnbull promised more resources so the visa appeal processes would be faster.
But Maori Party co-leader Marama Fox said the situation was volatile and the New Zealand Government needed to do much more.
"A delegation should be allowed to go to Christmas Island to ascertain the safety of all those there, especially expat Kiwis."
Mr Key said incidents at the detention centre were a matter for the Australian government and he would not be intervening.
"I'm always concerned about New Zealanders but they are in a corrections facility [where] actually they are free to leave... They are staying there voluntarily."
If any of the detainees had concerns they could contact the New Zealand Government, he said.
As far as he understood, the process was being speeded up and New Zealand detainees given priority.
"I can't tell you exactly what the pathway was but the assurance we got from the Australians is they're putting in a lot more resources... but the question is how quickly [they] can deal with those appeals."
Mrs Fox dismissed the suggestion detainees could leave whenever they wanted.
"It's almost a ridiculous statement because they have to sign away their visa rights in order to do that. "These are people whose lives have been established in Australia. They want to go home to their families who are in Australia - not in New Zealand."
An Australian lawyer who acts for New Zealanders in detention, Greg Barns, said tensions had been building for some time over delays.
"I'm not aware of any acceleration whatsoever and I'm relatively close to the situation. John Key needs to pick up the phone to Malcolm Turnbull and say, 'you gotta fix this'."
Christmas Island was a "desolate place" and the centre should be shut down, he said.
"You've had people who have been effectively taken from their families, placed in detention, and in some cases, as we know, they've been living in Australia for long periods of time.
"There's frustration about the way their cases are moving, which is fairly slow."