The gesture ahead of the team's Asian Cup match against South Korea last week was seen by many as an act of defiance against the Islamic republic just two days after the United States and Israel attacked it.

"I just spoke to Prime Minister Anthony Albanese, of Australia, concerning the Iranian National Women's Soccer Team. He's on it! Five have already been taken care of," Trump said Monday on his Truth Social network, less than two hours after an initial post urging Australia to take them in.

Trump added that "some, however, feel they must go back because they are worried about the safety of their families, including threats to those family members if they don't return."

There was no immediate comment from the Australian government, which has so far declined to say whether it could offer the players asylum.

Asked about their case on Sunday, Foreign Minister Penny Wong said Australia "stands in solidarity" with the people of Iran.

The son of Iran's late shah, US-based Reza Pahlavi, warned on Monday that the refusal to sing the anthem could have "dire consequences", and urged Australia to offer the team protection.

Trump then weighed in, pressing Albanese to "give ASYLUM" to the team and adding: "The US will take them if you won't."

"Australia is making a terrible humanitarian mistake by allowing the Iran National Woman's Soccer team to be forced back to Iran, where they will most likely be killed," the US leader said on Truth Social.

Pahlavi, who has not returned to Iran since before the 1979 Islamic revolution that ousted the monarchy, has billed himself as the man to lead a democratic transition to a secular Iran as the theocratic regime fights to survive.

Politicians, human rights activists and even "Harry Potter" author J.K. Rowling have also called for the team to be offered official protection.

"Please, protect these young women," Rowling said in a post on social media.

- 'Save our girls' -

A presenter on Iranian state TV had branded the players "wartime traitors" after they stood motionless during the anthem before their match against South Korea.

In subsequent games, the players saluted and sang.

Crowds gathered outside the Gold Coast stadium where the side played their last match over the weekend, banging drums and shouting "regime change for Iran".

They then surrounded the Iranian team bus, chanting "let them go" and "save our girls".

On Monday, an AFP journalist saw members of the team speaking on phones from their balcony of their hotel.

Asked about the possibility of granted asylum, a spokesperson for Australia's Home Affairs department told AFP earlier it "cannot comment on the circumstances of individuals".

Amnesty International campaigner Zaki Haidari said they faced persecution, or worse, if they were sent home.

"Some of these team members probably have had their families already threatened," Haidari told AFP.

"Them going back... who knows what sort of punishment they will receive?"

Despite being heavily monitored, the side would have a "small window of opportunity" to seek asylum at the airport, he said.

Iran's embassy in Australia did not respond to a request for comment.