The first of 12,000 Syrian and Iraqi refugees to be resettled in Australia under an arrangement announced by former prime minister Tony Abbott in his last days in office will arrive in Perth on Tuesday.

The family of five are due to arrive in Western Australia in the next 24 hours, social services minister, Christian Porter, said on Monday.

Porter told reporters at a press conference in Perth that the family was part of a group selected following a “rigorous” security screening process.

“But we’re talking, of course, about people here and in the case of this family understand who have been in refugee camps for very long periods of time,” he said.

“So there is a very high level of ability of the Australian government to assess them in a very rigorous way.”

The announcement comes after attorney general, George Brandis, dismissed calls from New South Wales Nationals MP Andrew Fraser for Australia to close its borders to “Middle Eastern refugees or Islamic boat people”. Brandis said the Muslim community was “a very important element of Australian society”, adding “the worst thing we could do is alienate the Muslim community”.

Australia announced plans to admit another 12,000 Syrian and Iraqi refugees in September in response to images of the refugee crisis in Europe, on top of the existing refugee intake of 13,750 refugees. A number of the additional refugees are expected to be Christian but the intake will not exclude Muslims.

At least 1,000 of those are expected to be settled in WA.

Porter said the one-off expansion of the refugee intake would put pressure on service providers but said the support system in Australia was “world class”.

“They don’t stop after a given period of time, they go on, they involve everything from health and trauma counselling, if that is required, to interface with government and government services, English language training and proficiency,” he said.

“We’re very good at it, actually, and it goes on for some period of time. So those normal processes will be applied to this family but no doubt everyone will be on their absolute toes to ensure that the service is at its sparkling best when we’ve got families like this who are coming in after long periods of being in very, very difficult circumstances.”

The announcement of additional humanitarian visa places was made at the same time the Australian government announced it would be joining US-led air strikes in Syria.

The first group of 200 were selected about two months ago and are expected to be resettled in Australia by Christmas. The immigration minister, Peter Dutton, said at the time everyone in the group would be subjected to rigorous testing.

“We are going to do biometrics testing, we are going to do some DNA testing otherwise, and we are going to search databases to make sure that people who come to this country are not going to pose a threat,” Dutton said.

“We offer a helping hand, but we aren’t going to inadvertently let people in who are going to do harm to the men, women and children of Australia.”

The process will cost $700m and Australia has also committed an extra $44m in humanitarian assistance.