President Donald Trump suffered a legal blow on Thursday when a federal appeals court refused to reinstate his executive order temporarily banning people from seven Muslim-majority countries from entering the United States.

A three-judge panel of the 9th U.S. Circuit Court of Appeals unanimously ruled that the Trump administration failed to offer any evidence that national security concerns justified immediately restoring the ban, which he launched two weeks ago.

Shortly after the court issued its 29-page ruling, Trump tweeted: "SEE YOU IN COURT, THE SECURITY OF OUR NATION IS AT STAKE!" He told reporters his administration ultimately would win the case and dismissed the ruling as "political."

The 9th Circuit ruling, upholding last Friday's decision by U.S. District Judge James Robart to suspend the order, does not resolve the lawsuit. It relates only to whether to lift an emergency halt to Trump's order put in place by a lower court.

Trump, a Republican who took office on Jan. 20, faces long odds in getting the ban restored while litigation over his executive order proceeds. To ultimately win, the Justice Department will have to present evidence that people from those countries represent a domestic threat, legal experts said.

In its ruling on Thursday, the 9th Circuit said the government had so far failed to show that any person from the seven countries had perpetrated a terrorist attack in the United States.

Trump's Jan. 27 order, the most divisive action of his young presidency, sparked protests and chaos at U.S. and overseas airports on the weekend after it was issued. It was challenged by the states of Washington and Minnesota, which argued it violated constitutional protections against religious discrimination.

The Justice Department, which spoke for the administration at oral argument on Tuesday, said it was reviewing Thursday's decision and considering its options.

Asked about Trump's tweet, Washington state Attorney General Bob Ferguson said: "We have seen him in court twice, and we're two for two."

Trump says his executive order aims to head off attacks by Islamist militants. He has voiced frustration at the legal challenge to his order, calling Robart a "so-called judge" whose "ridiculous" opinion "essentially takes law-enforcement away from our country."  

The 9th Circuit judges said more legal arguments would be needed to decide the actual fate of Trump's order.

While the court said it could not decide whether the order discriminated against a particular religion until the case had been “fully briefed," it added that the states had presented evidence of “numerous statements” by the president “about his intent to implement a ‘Muslim ban.’”

The administration argued that the courts do not have access to the same classified information about threats to the country that the president does. The judges countered that “courts regularly receive classified information under seal.”

The three judges said the states had shown that even temporary reinstatement of the ban would cause harm.

FINAL OUTCOME 'NOT CERTAIN'

Curbing entry to the United States as a national security measure was a central premise of Trump's 2016 presidential campaign, originally proposed as a temporary ban on all Muslims.

U.S. presidents have in the past claimed sweeping powers to fight terrorism, but the 9th Circuit on Thursday wrote that courts have the authority to review whether the president violated the Constitution.

Two of the three 9th Circuit judges were appointees of former Democratic Presidents Jimmy Carter and Barack Obama, and one was appointed by former Republican President George W. Bush.

The government has 14 days to ask the 9th Circuit to have a larger panel of judges review the decision "en banc," or appeal directly to the U.S. Supreme Court, which will likely determine the case's final outcome.

But it would need five of the eight justices to vote in favor of suspending the travel ban during litigation. That is likely to be a tall order as the court is evenly divided 4-4 between liberals and conservatives, meaning the administration would need to win over at least one of the liberal justices.

Senior White House adviser Kellyanne Conway told Fox News: "It's an interim ruling and we're fully confident that now that we will get our day in court and have an opportunity to argue this on the merits we will prevail."

Asked if the administration would go to the Supreme Court, she said: “I can't comment on that. ... He will be conferring with the lawyers and make that decision.”

The Council on American-Islamic Relations, the nation's largest Muslim civil rights and advocacy organization, said Trump's policies "still pose a threat to communities of color, religious minorities, women, and others."

Democrats, the minority party in Congress, celebrated.

"This Administration’s recklessness has already done significant harm to families, and undermined our fight against terror," House Democratic leader Nancy Pelosi said in an emailed statement.

But Tom Fitton from the conservative group Judicial Watch said on Twitter: "The Ninth Circuit ruling is a dangerous example of judicial overreach."