Foreign Minister Julie Bishop has described conditions at the Nauru immigration processing centre as being better than those of most Australian mining camps.

Ms Bishop's comments follow a damning UNHCR report last month, which said the centre was not appropriate for asylum seeker families and their children.

Ms Bishop visited the centre as part of a three-day bi-partisan tour of the Pacific, which also included Solomon Islands and Vanuatu.

She maintains the living standards are high for the more than 700 asylum seekers currently on Nauru.

"They were certainly better than mining camps in Australia," Ms Bishop said. "The standard of medical care and services I thought was very high.

"We met with a number of the doctors. We talked to them in detail about the services that they're providing. They themselves described the services as comparable to those that would be received in a significant regional centre in Australia."

But Opposition deputy leader Tanya Plibersek, who is accompanying Ms Bishop on the Pacific tour, has voiced some concern.

It was the Labor government which re-started offshore processing on Nauru and Papua New Guinea's Manus Island.

"I did see the recreational facilities that have been built in one of the camps, but I can't say what was happening in the other two because I wasn't able to visit those camps," Ms Plibersek said.

"Nauru is a very small island. It's got a regular population of around 10,000. It's hot, it's quite dry... it's not an easy environment to live in for the Nauruans themselves," she said.

"So I'd say the conditions for the detainees would be similar to the conditions for the Nauruans. But of course they don't have the same freedom of movement."

The Nauru facility has been heavily criticised in recent weeks, with questions raised over its standards.

The United Nations High Commissioner for Refugees (UNHCR) called on the Australian Government to stop sending asylum-seeker children to the detention centres, singling out the Nauru centre in particular, saying it is rat-infested, cramped and very hot.

Greens Senator Sarah Hanson-Young recently toured the facilities on Nauru and says the conditions are inhumane and completely inappropriate for children.

"It's in the middle of the island in the middle of the mine, a quarry. There is no grass, there's no forest, there's not even really dirt. It's just rock and gravel," Ms Hanson-Young said.

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She is especially concerned about the conditions for more than 100 children detained on the island.

"There are children as young four years old in the camp there, up to the ages of 18. There is a number of unaccompanied minors," she said.

"It really struck me on the way home when I was reflecting on the visit that I'm going to spend the weekend buying Christmas presents for my daughter and these kids have nothing, absolutely nothing. And they just kept pleading with me the entire time: 'Why are we in this prison, and what have we done wrong?'"

Ms Bishop says she did not see any asylum seeker children while touring the facilities, but maintains conditions are appropriate.

"They do have schooling. They have been going to the local school," she said.

"I also went to recreational facilities; I saw opportunities for them. So I think that there are plenty of things for them to do there.

"It may be different from their home country, but most certainly the Australian Government is spending a significant amount of money on services, including recreational facilities".

Questions remain over Pacific aid assistance

The bipartisan Pacific delegation has also visited Solomon Islands and Vanuatu, with a special focus on women and girls.

In Vanuatu, the Foreign Minister unveiled plans to provide $37 million to help improve 350km of roads, while in Honiara, Ms Bishop said Australia would spend more than $20 million for various social and investment projects.

The pledges come despite the Australian Government's plans to scale back the foreign aid budget.

Pacific Island nations and aid groups have been waiting to hear exactly what the projected reduction in growth in foreign aid will mean for them.

Ms Bishop has revealed little detail but she says changes can be guaranteed.

"What we have to do is trim the budget across many sectors of the Australian Government," she said.

"In relation to aid, we will focus our efforts on our region and in that way we'll be able to make a significant difference to the lives of people in our region. So I'm trying the best I can to ensure that our aid is delivered more effectively, more efficiently," she said.