Iranian tourists with valid visas will be banned from visiting Australia for the next six months over concerns they may be unable or unlikely to return home once their visas expire.

"Decisions about permanent stays in Australia should be deliberate decisions of the government, not a random consequence of who had booked a holiday," Home Affairs Minister Tony Burke said on Wednesday.

The move, which comes into force on Thursday, will affect about 6,800 Iranian visa holders. Some exceptions have been made including for the partners and children of Australian citizens.

Some MPs and refugee advocates have called the decision a "moral failure" and warned it sets a "dangerous precedent".

The Australian government introduced legislation to block visa holders from nominated countries from visiting earlier this month, on the same day it granted humanitarian visas to seven members of the Iranian women's football delegation. Five later returned to Iran.

Burke said in a statement that the government was "acting in the national interest amid rapidly changing global conditions", noting that the measure would allow "time to assess the situation properly, while still allowing flexibility in limited cases".

"Sympathetic consideration" may be given to the parents of Australian citizens, Burke said. The step was taken in consultation with the Australian-Iranian community, he added.

The measure does not apply to citizens from any other country.

Jana Favero, Deputy CEO of the Asylum Seeker Resource Centre, described the move as a "massive betrayal of the Iranian community, and a breathtaking moral failure".

"In the moment that people need safety the most and their country is being torn apart, the Albanese government is slamming the door closed on people from Iran," Favero said.

Independent MP Zali Steggall said the laws underpinning the ban gave the government "sweeping, unchecked" powers and ought to be amended.

"Invalidating lawfully obtained visas undermines confidence in our entire migration system and sets a dangerous precedent," she said.

The Australian Greens party said the measure "puts the lie to the pretence that [the] Labor [government] is supporting the illegal US and Israeli war on Iran to help the Iranian people".

"Today, we see with 100% clarity what the Albanese government thinks of the safety of the Iranian people as they shut the door on protection for people with a visa to come here," Greens Senator David Shoebridge said.