Australian dual national passport holders will be able to enter the US despite President Donald Trump's executive order banning entry from seven Muslim-majority nations, Prime Minister Malcolm Turnbull confirmed on Tuesday, China's Xinhua news agency reported.

There were fears that dual national Australians who hold a passport from Iran, Iraq, Libya, Somalia, Sudan, Syria or Yemen would be turned around at the US borders after Trump ordered the 90-day travel ban for those nations, but Turnbull said Australians who hold a second passport will be allowed to come and go from the US "in the usual way."

"Our Ambassador (to the United States) has just called me to say he has assurances from the White House that Australian passport holders, regardless of their place of birth or if they're dual nationals, will remain welcome to come and go to the United States in the usual way," Turnbull told Sky News.

The Turnbull government said it supports the United States' right to protect its borders, but the opposition and other politicians have labeled the prime minister "weak" while other world leaders, including those from Britain and Germany, denounced Trump's executive order.

It is believed that more than 110,000 Australians were born in the seven banned nations, with many holding dual passports. They will no longer be affected by the ban.

Despite Tuesday morning's developments, the opposition has increased pressure on the government to join other nations in condemning the immigration ban.

Shadow Attorney-General Mark Dreyfus told the Australian Broadcasting Corporation (ABC) that Turnbull showed a lack of "moral leadership" in not denouncing Trump's executive order.

-- BERNAMA