President Donald Trump stepped up his criticism of the U.S. judiciary on Wednesday, saying courts seem to be "so political," a day after his U.S. travel ban on people from seven Muslim-majority countries faced close scrutiny from an appeals court. A three-judge panel of the San Francisco-based 9th U.S. Circuit Court of Appeals on Tuesday heard arguments on the Trump administration's challenge to a lower court order putting his temporary travel ban on hold. Trump on Saturday accused the judge who issued the order of opening the United States to "potential terrorists." The appeals court is expected to issue a ruling as soon as Wednesday. "I don't ever want to call a court biased," Trump told hundreds of police chiefs and sheriffs from major cities at a meeting in a Washington hotel. "So I won't call it biased. And we haven't had a decision yet. But courts seem to be so political. And it would be so great for our justice system if they would be able to read the statement and do what's right." "I think it's a sad day. I think our security's at risk today." The appeals court must decide whether Trump acted within his authority or violated the U.S. Constitution's prohibition on laws favoring one religion over another, as well as anti-discrimination laws, and was tantamount to a discriminatory ban targeting Muslims. The 9th Circuit is expected to decide the narrow question of whether a lower court judge acted properly in temporarily halting enforcement of the president’s order. While the court could take into account the strength of the arguments on both sides, this is just a first step in a fast-moving case. The appeals court judges questioned whether the directive improperly targeted people because of their religion. Trump's Jan. 27 order barred travelers from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen from entering for 90 days and all refugees for 120 days, except those from civil war-torn Syria, whom he would ban indefinitely. "DO WHAT THEY SHOULD" Trump, a Republican who took office on Jan. 20 and has made extensive use of unilateral presidential directives that bypass Congress, has defended the directive as necessary to prevent attacks by Islamist militants. "If these judges wanted to, in my opinion, help the court in terms of respect for the court, they'd do what they should be doing," he told the law enforcement officials. Trump praised a federal judge in Boston who earlier ruled in his favor on the travel ban as a "highly respected" jurist whose findings were "perfect." Trump on Saturday labeled U.S. District Judge James Robart of Seattle, who put his directive on hold last Friday, as a "so-called judge" who made a "ridiculous" ruling. Robart was appointed to the bench by Republican President George W. Bush. Last year, Trump accused Indiana-born U.S. District Court Judge Gonzalo Curiel of bias in overseeing a lawsuit against one of Trump's businesses, Trump University, because of his Mexican heritage. Democrats and other critics have called Trump's comments toward the judiciary an attack on a core principle of American democracy that the courts are independent and uphold the rule of law. Under the Constitution, the judiciary is a co-equal branch of the U.S. government, along with Congress and the president's executive branch. At the meeting with law enforcement officials, Trump read from the law he cited to justify the travel ban, quoting it in fragments and sprinkling bits of interpretation. He said the law clearly allowed a president to suspend entry of any class of people if he determines them to be a detriment to national security. "A bad high school student would understand this," Trump said. "Anybody would understand this." "SECURITY AND SAFETY" In a Twitter post earlier on Wednesday, Trump wrote, "If the U.S. does not win this case as it so obviously should, we can never have the security and safety to which we are entitled. Politics!" U.S. State Department figures showed that 480 refugees have been admitted to the United States since Robart's order went into effect, including 168 on Wednesday. Of those admitted, 198 were from war-torn Syria. During an oral argument lasting more than an hour on Tuesday, the appeals court panel in San Francisco pressed an administration lawyer over whether the Trump administration's national security argument was backed by evidence that people from the seven countries posed a danger. Judge Richard Clifton, also appointed to the bench by Bush, posed equally tough questions for a lawyer representing Minnesota and Washington states, which are challenging the ban. The order, the most divisive act of Trump's young presidency, sparked protests and chaos at U.S. and overseas airports. Ultimately the matter is likely to go to the U.S. Supreme Court, which is ideologically split with four liberal justices and four conservatives pending Senate action on Trump's nomination of conservative appellate judge Neil Gorsuch to fill a lingering vacancy on the high court.