Trump plans travel ban appeal.

SAN FRANCISCO — President Donald Trump is sending his travel ban back to the 9th Circuit Court of Appeals for a second showdown, the administration said in a court filing Thursday, setting the stage for a key test of his presidential authority.

Making good on his promise to fight for his revised travel ban, Trump formally notified a federal court in Hawaii that he will appeal the ruling that suspended the ban earlier this month. The battle before the San Francisco-based appellate court will play a major role in determining the success of Trump’s first few months in office, with the case following the failure to repeal and replace the Affordable Care Act.

“The Department of Justice strongly disagrees with the federal district court’s ruling,” a department spokeswoman wrote in an emailed statement Thursday. “The President’s Executive Order falls squarely within his lawful authority in seeking to protect our nation’s security, and the department will continue to defend this executive order in the courts.”

The one-paragraph filing by the Trump administration did not lay out its arguments supporting the ban, which will come later in the case.

U.S. District Judge Derrick Watson in Hawaii suspended the executive order issued by Trump — which would have temporarily barred refugees from Somalia, Sudan, Yemen, Libya, Iran and Syria from entering the U.S. unless they already had visas — just hours before it was set to go into effect.

Ruling the state of Hawaii was likely to face “irreparable injury” if the travel ban was enacted, Watson issued a nationwide temporary restraining or- der that prevented enforcement of the ban.

Watson dealt the Trump administration another blow Wednesday by turning that temporary restraining order into a preliminary injunction, extending the suspension of the travel ban.

The 9th Circuit already ruled against Trump’s travel ban last month in another case, following a fiery telephone hearing with a three-judge panel.

In that case, a federal judge in the state of Washington had temporarily suspended the president’s first travel ban — which also barred immigrants from Iraq and did not carve out a protection for existing visa holders. Trump’s administration asked the 9th Circuit to “stay” the Washington court’s order and temporarily reinstate the ban, but the appellate judges refused.

Instead of pursuing his appeal, Trump returned to the drawing board and crafted a revised version of the travel ban, intending to fix the issues pointed out by the courts. But the state of Hawaii argued version two also violates the constitution and discriminates against immigrants on the basis of their nationality.

Rather than draft a third version of the travel ban if he loses again before the 9th Circuit, this time, Trump likely will see the appeal all the way through, said Rex Heinke, an appellate lawyer with the law firm Akin Gump in Los Angeles.

“It seems to be likely that the administration will take this to the Supreme Court,” he said. “The first travel ban seemed to be put together rather hastily and had not been thoroughly vetted. Here, the administration seems to have put more time and effort into it, and is presumably more committed to defending it.”

A judge in Maryland also has suspended part of the revised travel ban, prompting Trump to file a notice of appeal in that case as well.