The Australian government has asked New Zealand to keep its offer to take up to 150 refugees on the table, despite turning down the offer for five years, documents show.

In November last year, the New Zealand prime minister, Jacinda Ardern, reiterated her government’s offer to take up to 150 refugees after a weeks-long standoff at Manus Island detention facility led to a desperate humanitarian situation for the remaining detainees.

New Zealand has made the same offer to the Australian government since 2013, but it has been strongly and repeatedly refused. The Australian home affairs minister, Peter Dutton, described it as a “bad option” and suggested it may encourage people-smuggling boats to intensify their efforts to reach Australia.

“I don’t rule it out, I never have,” Dutton said at the time. “But at this point in time, it is the wrong decision to send people to New Zealand because in the end you’ll start the boats, people will fill up the vacancies we’ve created in Nauru, you’ll get the deaths at sea again. I’m just not going to preside over that arrangement.”

Despite Dutton’s reluctance, government papers obtained by Sky News show Australia asked the New Zealand government to keep its offer on the table, in case plans to re-home Manus Island detainees in the US fell through.

A memo from the Ministry of Foreign Affairs and Trade (Mfat) to Ardern also reveals the New Zealand offer was not without caveat, and New Zealand preferred to accept refugees in family units from Nauru, rather than the single men who were housed on Manus Island.

The documents from Mfat also raised concerns about whether the detainees would pass New Zealand’s strict screening laws, which include character and security tests.

Arif Saeid from the Refugee Council for New Zealand said the needs of the detainees held on Manus Island were “more desperate” than those on Nauru and the New Zealand government shouldn’t “cherry-pick” which refugees it offered help to.

“Single men are not more dangerous than other asylum seekers; often they do not have the resources to escape with their whole family so they come alone. It is discriminatory to not accept single men or single women.”

In 2001 Helen Clark’s Labour government offered asylum to 130 refugees who were rescued from the Tampa after it sunk off the Australian coast.

Twenty of the 130 asylum seekers were young boys and adolescents, and became known as the “Tampa boys”.

The United Nations refugee agency has repeatedly urged Australia to accept New Zealand’s offer, as recently as November last year.

“We urge Australia to reconsider this and take up the offer,” said Nai Jit Lam, deputy regional representative at the UNHCR.

New Zealand currently accepts 1,000 refugees every year, with the new Labour coalition government pledging to double that number in the next three years.

The New Zealand Red Cross, which is the main provider of community refugee resettlement programmes, said: “The Red Cross has the capacity to support a significant increase on top of the 1,000 people we currently resettle each year. We are concerned about the situation on Manus and Nauru. New Zealand Red Cross is ready to support the resettlement of any new arrivals and is working closely with our Australian and international counterparts.”

• This article was amended on 17 April 2018 to correct the number of refugees New Zealand accepts each year from 750 to 1,000 and clarify the statement from the Red Cross.