The Trump administration has filed its final brief to the Supreme Court in its bid to reinstate a travel ban.
The justices are set to meet today in their last scheduled conference before the summer recess.
Earlier this month an appeals court blocked a proposed 90-day travel ban on travel to the US from six Muslim-majority countries.
It was the latest failed attempt by the US President to impose the controversial ban.
The three appeals court judges said they were unanimous in their decision that Trump’s executive order violated the First Amendment’s prohibition of government establishment of religion.
They said: "The order does not offer a sufficient justification to suspend the entry of more than 180 million people on the basis of nationality."
But the administration argues that the countries included in a revised order are at heightened risk for terrorism.
An original ban was put into place shortly after Trump came into office in January but led to protests across the country.
It was blocked after a legal challenge initially mounted by Washington state and Minnesota.
A revised order was then signed in March to try to address legal issues, and Iraq was removed from the list.
But a district court in Maryland found the revised ban violated constitutional rights and blocked it before it could take effect. A federal judge in Hawaii also ruled the ban was discriminatory.
