The message is in the form of a video, and comes amid reports federal government plans to send the first group of refugees are being delayed because of a lack of willingness by detainees to go.
Under the agreement signed last year, refugees can only be sent from Nauru to Cambodia on a voluntary basis, with the number of refugees to be determined by Cambodia.
Meanwhile Cambodian-Australian community groups are condemning the 40 million dollar refugee resettlement deal.
They claim refugees are being bullied into being sent to a country with a poor human rights record.
Under the deal signed last year, refugees whose claims were assessed on Nauru will be able to resettle in Cambodia if they choose to do so.
The Cambodian government will receive the funding in the form of foreign aid from Australia, and it will be up to the Cambodian government to determine how many refugees it will accept from Nauru.
Immigration Minister Peter Dutton says as Cambodia is a signatory to the United Nations Refugee Convention, he is confident the refugees will be resettled well in the southeast Asian nation.
Mr Dutton has released a video, warning the refugees that if they don't accept the offer to travel to Cambodia now, they could end up spending up to ten years or more on Nauru, with no prospect of ever being resettled in Australia.
In the video, the Immigration Minister explains the refugees will be offered cash, employment assistance and Khmer language classes if they take up the offer to settle in Cambodia.
"This package will assist refugees to establish new lives in Cambodia and is available to those who decide to travel as part of the first group to Cambodia. There is no guarantee that this level of support will be offered to people who wait and do not commit to this first group."
The refugee resettlement deal has attracted criticism from a number of opposition MPs and student groups in Cambodia.
They fear the money from the resettlement deal could end up in the hands of corrupt Cambodian officials.
Cambodia-born Victorian state Labor MP Hong Lim is an honorary advisor to a number of Cambodian-Australian community groups.
He's also Victoria's parliamentary secretary for Multicultural Affairs and Asia Engagement.
Mr Lim says the refugee deal is fundamentally flawed and is already generating a lot of concern within Cambodia.
"There have been two major demonstrations in front of the Australian embassy and this has never happened before to a western country (in Cambodia). They're going to create a very privileged class of refugee there. The local people are going to ask 'What about me?' You (the Cambodian government) took my home. You took my land. You took my house and now you give all this to these people. Who are they?"
The Refugee Council of Australia accuses the federal government of effectively bullying a poorer neighbour into accepting aid in exchange for refugees.
CEO Paul Power says the Cambodian government has had a poor record on asylum-seeker policy, sending back many Muslim Uighurs to face ongoing persecution in China.
Mr Power says the Cambodian economy is also very weak and many of the refugees could struggle to find employment if they opt to settle there.
"To move refugees from one country where it's not possible for people to remain sustainably to another country where the refugees are going to really struggle to be able to re-establish themselves is really setting people up for failure and it's clearly against the spirit of the way in which international refugee protection and refugee resettlement works."
Immigration Minister Peter Dutton has strongly defended the deal with Cambodia, arguing that refugee resettlement is not an economic migration program.
He has described Cambodia as a fast-paced and vibrant country with a stable economy and a culturally and religiously diverse population.
Associate Professor Alex Reilly specialises in immigration law at the University of Adelaide.
He agrees with concerns raised by refugee advocates over Cambodia's human rights record and its treatment of asylum seekers.
Dr Reilly says many of the refugees likely to leave Nauru were born in the Middle East and they could struggle to settle into a country like Cambodia.
"When you don't speak the language, you're part of an education system that is a poor education system, its public infrastructure is poor- when you've got people who are from a different religion and a different language and they don't have the kind of government support that we understand in a modern, developed nation like Australia, there has to be grave concerns whether the people sent to Cambodia will be able to set up a new life there."
