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.
"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.
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 ETSA is an online application that determines entry eligibility based on security or police risks.
This also includes government officials or defence force members who are dual citizens of Iran, Iraq, Syria or Sudan, but there may be exceptions for some who travelled on official government or defence business.
All those affected will have to apply for a non-immigrant visa at a US embassy or consulate.
