The 15-page brief filed with the San Francisco-based Ninth Circuit Court of Appeals asserted that the executive order Trump signed late last month was a "lawful exercise of the president's authority".
The department argued the seven majority-Muslim countries blacklisted for travel to the U.S. were identified for terror risk, and therefore it is "incorrect" to call it a Muslim ban as it was "neutral with respect to religion".
Before it was halted following a Seattle, Washington, federal court's restraining order, the executive action caused tens of thousands of visa revocations and dozens of arrests at airports, triggering mass demonstrations across the country.
It bars nationals of Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen from entering the U.S. for 90 days, and freezes the government's entire refugee program for 120 days. Syrians are banned indefinitely, while Syrian Christians are prioritized for entry.
The Justice Department said the Washington court "erred in entering an injunction barring enforcement of the order.
"But even if some relief were appropriate, the court's sweeping nationwide injunction is vastly overbroad," it said.
After the Washington court's restraining order, acting Attorney General Sally Yates questioned the legality of the executive action and refused to defend it, prompting Trump to fire her from her post.
A panel of three federal judges will hold a hearing Tuesday to decide whether to reject the ban.