The UN’s refugee agency has slammed Australia in a statement for reportedly informing the agency it would no longer accept refugees it had previously agreed to take in, telling the body to relocate them to the US or Cambodia instead.

Vivian Tan, a spokeswoman for the UN High Commissioner for Refugees in Bangkok, said the body is concerned about Australia’s “outsourcing” of refugees to other countries after it struck deals with the US and Cambodia to take in many of the refugees it has controversially detained in Nauru and Papua New Guinea for years.

“We were also concerned about implementation challenges and that sending large numbers of refugees to Cambodia – which is not a resettlement country – could challenge its absorption capacity,” Tan said.

In its statement, the UNHCR said it had “no other choice” but to recommend the relocation of all refugees to the US.

Tan said the UNHCR could not comment on whether Australia had plans to send more refugees to Cambodia.

Kerm Sarin, director of administration at the Ministry of Interior’s Refugee Department, said he had not heard of any plans to relocate additional refugees from Nauru to Cambodia.

The 2014 deal between Australia and Cambodia to resettle the refugees was controversial, with human rights groups accusing the Australian government of offloading its obligation to other countries. Australia agreed to give approximately A$40 million in aid to Cambodia as part of the deal.

Only seven people have been resettled in Cambodia since 2014, and of those, only three remain. The rest chose to return to their countries of origin.

Roughly 1,100 refugees are still detained on Nauru after attempting to reach Australia, according to Ian Rintoul, a spokesman for the Refugee Action Coalition in Sydney, a refugee advocacy group.

He said most of those who remain on Nauru do not want to go to Cambodia.

“There’s no future, no security, no way to get educated or get the things they left their own countries for,” Rintoul said. “The only people that have ever gone to Cambodia saw it as a stepping stone to get out of Nauru to get somewhere else.”

Chris Lom, a spokesman for the International Organization for Migration in the Asia-Pacific region, which was tasked by the Australian government with helping resettle the refugees in Cambodia, also said he believes that most refugees did not want to come to Cambodia.

“The fact that they thought they would go to the US or to Australia means that Cambodia will be a down-the-list priority,” Lom said.

The Australian Department of Immigration and Border Protection could not be reached.