SYDNEY (Reuters) - The U.N. refugee agency on Tuesday urged Australia to accept New Zealand’s offer to resettle 150 refugees from an abandoned Australian-run detention center in Papua New Guinea, as about 450 men remain barricaded inside without food or water.

An undated image released November 13, 2017 shows detainees staging a protest inside the compound at the Manus Island detention centre in Papua New Guinea. Refugee Action Coalition/Handout via REUTERS

The asylum seekers have been holed up inside the center for the past two weeks defying attempts by Australia and Papua New Guinea to close the facility, saying they fear for their safety if moved to transit centers.

With many detainees complaining of illness bought about by the unsanitary conditions in the camp, the U.N. High Commissioner for Refugees (UNHCR) urged Australia to allow 150 of them to resettle in New Zealand.

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

Most of the asylum seekers are from Afghanistan, Iran, Myanmar, Pakistan, Sri Lanka and Syria.

Australia’s “sovereign borders” immigration policy, under which it refuses to allow asylum seekers arriving by boat to reach its shores, has been heavily criticized by the United Nations and human rights groups but has bipartisan political support in Australia.

Australia says allowing asylum seekers arriving by boat to reach its shores would only encourage people smugglers in Asia and see more people risk their lives trying to sail to Australia.

Two motions introduced in Australia’s parliament by the Labor and Green parties, and passed in the upper house on Tuesday, call on Prime Minister Malcolm Turnbull to approve the New Zealand proposal.

“This is a foul and bloody stain on Australia’s national conscience,” Greens senator Nick McKim told reporters.

Turnbull this month rejected the refugee resettlement offer from his New Zealand counterpart, Jacinda Ardern, preferring instead to work through an existing refugee swap deal he negotiated with former U.S. President Barack Obama last year.

Under the U.S. deal, up to 1,250 asylum seekers detained by Australia in Papua New Guinea and Nauru in the South Pacific could be resettled in the United States in return for Australia accepting refugees from Central America. So far, the United States has accepted only 54.

Despite Turnbull rejecting the offer, Ardern this week said it remained on the table and she would seek a second meeting with Turnbull to discuss the “unacceptable” situation inside the Manus island detention center.

Water and electricity to the center were disconnected two weeks ago after Australian security withdrew and the camp closed on Oct. 31. The camp gad been declared illegal by a Papua New Guinea Court.

Papua New Guinea has threatened to forcibly move the men if they remain inside the center. It has set three deadlines but all have passed largely without incident.