The Coalition’s $55m refugee deal with Cambodia is a “pretty good outcome”, the immigration minister, Peter Dutton, has said, despite only two people resettling in the country.

Only two of five people who agreed to move from Australia’s offshore detention centre on Nauru to the south east Asian country remain.

“I think that is a pretty good outcome,” Dutton told the Nine Network on Wednesday.

Asked if the $55m cost of the deal amounted to a waste of taxpayers’ money and an expensive stopover for Australia’s rejected boat arrivals, Dutton said the government was determined to crush people-smuggling operations and stop people drowning at sea.

“We have been very clear about the fact if you come to Australia by boat you will never settle here,” he said.

The Cambodia deal comprises $40m in aid and $15m for resettlement costs.

An Iranian couple moved from Nauru to Cambodia voluntarily left the country in late February.

Another refugee, an ethnic Rohingya, went back to Myanmar (Burma) last October.

That leaves one person left in Cambodia from the original group of four resettled under the Australian program.

The opposition immigration spokesman, Richard Marles, said on Tuesday it was “all but over for the botched deal”.

“The inability of this government to secure a meaningful resettlement arrangement with a credible third country is a serious failure,” he said.

Cambodia has indicated it was not prepared to accept any more refugees.

But Australia appears to remain committed to supporting the Cambodian government to implement settlement arrangements and is still encouraging refugees on Nauru to explore Cambodia as a resettlement option.

Refugees can elect to return to their country of origin at any time.