Supreme Court Chief Justice John Roberts issued a temporary order allowing the Trump administration to continue construction on its $400 million White House ballroom project while legal challenges move through the courts.

The administrative stay temporarily freezes a federal appeals court ruling that would have halted aboveground construction. A three-judge panel from the U.S. Court of Appeals for the D.C. Circuit had previously determined that the 90,000-square-foot expansion lacked required congressional approval, setting a deadline to pause work.

In emergency filings to the high court, the administration argued that the project—which includes an integrated underground military and security installation—is critical to national security and protection of the president. Government lawyers maintained that halting work would disrupt essential security upgrades designed to shield the facility.

Preservation groups and critics challenging the project contend the administration lacks the authority to make massive structural alterations to the historic East Wing without explicit authorization and funding from Congress.

The Chief Justice’s order buys time for the full Supreme Court to review the administration’s emergency application and decide whether to issue a longer-lasting stay while the broader appeal plays out.