The fourth group of refugees to be accepted for resettlement in the United States from Australia’s offshore immigration regime are poised to leave Nauru for the US, via Fiji.

The 22 refugees are all single men except for one Rohingyan man and his wife, according to Ian Rintoul from the Refugee Action Coalition.

It is the second group to leave Nauru under the controversial resettlement program, following two groups that have also been resettled from Australia’s detention centre on Manus Island in Papua New Guinea.

The latest cohort will bring the number of refugees resettled in the US to about 110. About 2,000 refugees and asylum seekers remain in Australia’s offshore system.

The controversial “US deal” – decried as “dumb” but upheld by the US president Donald Trump – was brokered by his predecessor Barack Obama and the Australian prime minister, Malcolm Turnbull, in September 2016.

In exchange for the US considering to resettle 1,250 refugees from Australia’s offshore camps, Australia has agreed to take refugees from US-run refugee camps in Costa Rica. Those refugees are from the violence-plagued northern triangle countries of central America: El Salvador, Guatemala and Honduras.

Rintoul said all the refugees in the new cohort are Afghans, Pakistanis and Rohingya. The makeup further confirms fears that Iranians, who make up the largest national group on Nauru, will be excluded from the US intake.

Iran and Somalia were both proscribed by Trump’s “travel ban”. It is unclear what impact the executive order will have on the US resettlement deal brokered before Trump came into office. The order suspends the entry into the US of nationals from Chad, Iran, Libya, Somalia, Syria, Yemen, North Korea and Venezuela.

According to the Refugee Action Coalition, one of the Rohingyan men being resettled has family in Australia. They say the man was been told that if he declined to go to the US, he could expect to be on Nauru for 20 years, or could go to Cambodia.

In December, the Guardian reported that Australian Border Force officials were telling refugees on Nauru they must separate from their wives and children – and face never seeing them again – in order to apply for resettlement in the US.

Recordings of phone conversations and an email chain confirmed the ABF was encouraging permanent family separation, in contravention of international law, and directly contradicting evidence given to the Senate by the department secretary, Mike Pezzullo.

The Department of Home Affairs has been contacted for comment.

Ben Doherty contributed to this report