A woman whose great grandparents were murdered in Auschwitz has made an emotional plea to Prime Minister Malcolm Turnbull to stand up to US President Donald Trump about his Muslim immigration ban.

Sydney writer Mireille Juchau took to Twitter on Sunday to make the plea after President Trump signed an executive order on Friday making major changes to America's policies on refugees and immigration.

Ms Juchau said her great grandparents were denied asylum in Australia in 1939 and because of this became casualties of Adolf Hitler's Nazi regime.

Ms Juchau took to Twitter on Sunday posting a picture showing the refusal letter (pictured) that her grandparents received denying their application for entry into Australia

Sydney writer Mireille Juchau (above) whose great grandparents were murdered in Auschwitz has made an emotional plea to Malcolm Turnbull to stand up to the United States Muslim ban

She posted a picture under her tweet showing the refusal letter her grandparents received from the government denying their application for entry into Australia.

Ms Jushau elaborated even further on her Facebook saying the ban had similarities to the Holocaust and even quoted Austrian novelist Stefan Zweig.

'Australia denied my great grandparents entry in 1939. Five years later they were murdered in Auschwitz,' she wrote.

'I've been wary of the comparisons up till now but Trump's horrific Muslim ban makes the similarities impossible to ignore. That this racist ban was enacted on Holocaust Remembrance Day makes it all the more despicable.

'I am waiting in vain to hear our Australian leaders speak out against Trump's latest actions. The silence is unsurprising but fills me with despair. If they have, and I have missed it, please let me know.'

On Friday United states President Donald Trump (pictured) made major changes to America's policies on refugees and immigration

Trump's order bars any non-U.S. citizen from Iraq, Syria, Iran, Sudan, Libya, Somalia or Yemen from entering the United States.

That includes legal permanent residents - green card holders - and visa-holders from those seven countries. They cannot return to the U.S. for 90 days.

There's an exemption for immigrants and legal permanent residents whose entry is in the U.S. national interest, but it's unclear how that exemption will be applied.

Visa and green card holders already in the U.S. will be allowed to stay.

A federal judge in Brooklyn issued a nationwide, emergency stay on Saturday night to allow people with a valid visa to remain once they've landed in the US.

The decision did not strike down the executive order, and is only temporary.

Australians who hold passports from one of the seven Muslim-majority nations implicated by the Trump administration immigration ban may be affected by the controversial order.

A spokewoman for Foreign Minister Julie Bishop says officials are in talks with US counterparts to get clarity on how the temporary ban on those from Iraq, Iran, Libya, Somalia, Sudan, Syria and Yemen may affect dual nationals.

Ms Juchau (pictured) said her great grandparents were denied asylum in Australia in 1939

Ms Juchau pleaded with Prime Minister Malcolm Turnbull (pictured) to 'speak out' against the Muslim ban

Trump's order bars any non-U.S. citizen from Iraq, Syria, Iran, Sudan, Libya, Somalia or Yemen from entering the United States

'The Australian embassy in Washington is engaging with US officials on the potential implications of the suspension for Australian travellers, including dual nationals,' a spokeswoman told AAP in a statement.

All travellers are being warned that rules could change at short notice.

'Travellers should contact the nearest embassy or consulate of the United States for the most current information,' the spokeswoman added.

In February 2016 the US Department of Homeland Security added Libya, Somalia and Yemen to its existing list of Iran, Iraq, Sudan and Syria, limiting the visa waiver program travel for those who'd travelled there.

The government's Smarttraveller website says Australians who have travelled to any of the seven nations since March 2011 are not allowed to apply for a mandatory security check needed for entry to the United States.

Australians who are dual citizens of Iran, Iraq, Sudan or Syria are not allowed to apply for the standard electronic travel authorisation - ETSA - which travellers must complete before heading to the US.

The ESTA is an online application that determines entry eligibility based on security or police risks.

All those affected will have to apply for a non-immigrant visa at a US embassy or consulate.