The Supreme Court on Friday afternoon requested responses from states and groups that have challenged the constitutionality of the president’s order ending birthright citizenship for the children of immigrants without legal status and foreign residents.

The move is a signal that the justices will consider a request by the Trump administration asking the court to lift a nationwide pause on the policy as the underlying court challenges proceed. Should the justices side with the administration, the policy could go into effect in the 28 states, plus U.S. territories, that have not been named as challengers to the order.

The issue before the justices is the legality of a tool called a nationwide injunction, which enables a federal judge to temporarily freeze a policy across the country, rather than limiting a pause to the parties involved.

In its applications to the court, the Trump administration pushed back on nationwide injunctions. The tool has been used during Democratic and Republican administrations and a debate over such injunctions has simmered for years.

The case arrived at the court as an emergency application, and it represents the first time the legal battle over the president’s order to end birthright citizenship has reached the justices.