 -- President Trump's second travel ban is still being largely blocked by the courts after the latest decision was handed down Monday.

The 9th Circuit decided to uphold in large part the injunction on the second iteration of the travel ban, according to the ruling.

This revised version of the executive order suspended refugee admissions for 120 days and barred people from six majority-Muslim nations from entering the United States for 90 days while the administration reviewed vetting procedures.

A temporary restraining order was placed on this iteration in March in a case filed by the state of Hawaii.

"The president must make a sufficient finding that the entry of these classes of people would be 'detrimental to the interests of the United States,'" Monday's ruling states.

Trump tweeted Tuesday morning about the decision.

The three-judge panel of the U.S. Court of Appeals for the 9th Circuit Monday ruled unanimously that the president's overhauled travel ban "exceeded the scope of the authority delegated to him by Congress" under federal immigration law, because the executive order did not contain "a sufficient justification to suspend the entry of more than 180 million people on the basis of nationality."

The Hawaii court injunction, which found that the executive order likely ran afoul of the establishment clause of the Constitution, prohibited the administration from enforcing the two core provisions of the policy: a 90-day suspension of entry from nationals of six designated countries and a 120-day suspension of refugee admissions.

The 9th Circuit, however, narrowed the injunction to allow the administration to go forward with provisions of the executive order regarding an internal review of vetting procedures, a potentially significant development as the administration goes forward with its appeal to the nation's highest court.

All three judges on the 9th Circuit panel were appointed to the bench by President Bill Clinton.

The Trump administration petitioned the United States Supreme Court last week to lift the Hawaii court's injunction and to hear the case if the 9th Circuit ruled against the administration — as it did in large measure Monday. The high court is also considering whether to hear the government's appeal of a similar injunction issued by a federal judge in Maryland and has yet to decide if it will take up the cases.

In a filing with the Supreme Court Monday, the plaintiffs in the Maryland case argued that the controversy is about to become moot because the entry ban was meant to last for only 90 days and that period ends two days from now.

At the White House press briefing this afternoon, press secretary Sean Spicer said that the administration was reviewing the decision of the 9th Circuit.

"I think we can all attest that these are very dangerous times and we need every available tool at our disposal to prevent terrorists from entering the United States and committing acts of bloodshed and violence," he said. "We continue to be confident that the president's executive order to protect this country is fully lawful and ultimately will be upheld by the Supreme Court."

On Monday, Attorney General Jeff Sessions released a statement on the decision, saying “President Trump’s Executive Order is well within his lawful authority to keep the nation safe. We disagree with the Ninth Circuit’s decision to block that authority.” Sessions also referred to "recent attacks" that confirm threats to the U.S. are "immediate and real" in his statement.

At the heart of the 9th Circuit opinion Monday is the panel's determination that the president failed to show in his executive order that there were specific national security justifications for excluding nationals of the six designated countries (Iran, Libya, Somalia, Sudan, Syria and Yemen).

"The order makes no finding that nationality alone renders entry of this broad class of individuals a heightened security risk to the United States," wrote Circuit Court Judges Michael Daly Hawkins, Ronald M. Gould and Richard A. Paez. "The order does not tie these nationals in any way to terrorist organizations within the six designated countries. It does not identify these nationals as contributors to active conflict or as those responsible for insecure country conditions. It does not provide any link between an individual's nationality and their propensity to commit terrorism or their inherent dangerousness. In short, the order does not provide a rationale explaining why permitting entry of nationals from the six designated countries under current protocols would be detrimental to the interests of the United States."

The circuit court also held that Trump failed in the executive order to "reveal any threat or harm to warrant suspension of [refugee admissions] for 120 days and does not support the conclusion that the entry of refugees in the interim time period would be harmful."

The administration has argued, in defense of the travel ban, that the president used his broad powers to make immigration decisions to suspend immigration from the designated countries while the administration conducted a review of vetting procedures. Based on the conditions in those countries, the government made a determination that "the risk of erroneously permitting entry of a national of one of these countries who intends to commit terrorist acts or otherwise harm the national security of the United States is unacceptably high."

Because the 9th Circuit panel found that the order was in violation of federal immigration statutes, the judges declined to wade into the issue of whether the travel ban is an unconstitutional manifestation of Trump's alleged animus toward Islam, as the Hawaii plaintiffs and other challengers have contended.

Other court decisions on the travel ban, including the Hawaii ruling under review at the 9th Circuit, focused on the president's campaign rhetoric about a broad ban on Muslim immigration. Hawaii District Judge Derrick Watson wrote in his March ruling that there was "significant and unrebutted evidence of religious animus driving the promulgation of the executive order and its related predecessor."

The 9th Circuit's alternative approach could complicate the picture at the Supreme Court.

"The previous opinions in the case focused on the constitutional question: whether the order was motivated by an impermissible purpose to discriminate on the basis of religion," said ABC News' Supreme Court contributor Kate Shaw. "The 9th Circuit opinion reaches the same conclusion — that the order is in large part invalid — but takes a totally different route. It doesn't reach the constitutional argument at all, instead concluding that the order exceeded the president's statutory authority. This could conceivably provide some members of the Supreme Court with an alternative means by which to strike down the order, if they're dubious about the order but not totally convinced by the constitutional arguments against it or if they wish to avoid the difficult question of whether and when it's appropriate to rely on presidential statements or campaign statements."