An appeals court decision on whether to reinstate US president Donald Trump’s controversial travel ban is expected later this week.
This came as one of three judges asked whether it could be discriminatory if it affected only 15% of the world’s Muslims.
The executive order temporarily banned entry for all refugees and visitors from seven mainly Muslim countries, until it was halted last week.
There was an hour of oral arguments from both sides at the court in San Francisco on Tuesday with Judge Richard Clifton querying whether the ban discriminates against Muslims.
The case is likely to end up in the Supreme Court whatever the 9th US Circuit Court of Appeals decides.
The Justice Department urged the appeal judges to reinstate the banning order.
Lawyer August Flentje said Congress had authorised the president to control who can enter the country.
When asked to point to evidence that the seven countries affected – Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen – present a risk to the US, he said a number of Somalis in the US had been connected to the al-Shabab group.
Then a lawyer representing Washington state told the court that halting the executive order had not harmed the US government.
Solicitor general Noah Purcell said the ban had affected thousands of residents of the state, with students delayed as they tried to come to Washington and others prevented from visiting family abroad.