WASHINGTON, D.C. — The Supreme Court’s ruling Wednesday in a multimillion-dollar dispute over a collection of religious artworks will make it harder for some lawsuits to be tried in U.S. courts over claims that property was taken from Jews during the Nazi era.

The justices sided with Germany in a dispute involving the heirs of Jewish art dealers and the 1935 sale of a collection of medieval Christian artwork called the Guelph Treasure. The collection, called the Welfenschatz in German, is said to now be worth at least $250 million.

The heirs argued that their relatives were forced to sell the collection of gold and silver artworks, including elaborate containers used to store Christian relics, intricate altars and ornate crosses, for below market value.

The heirs originally pressed their claims in Germany, but a German commission found the artworks’ sale was made voluntarily and for fair market value. A suit was then filed in the United States. Germany and the state-run foundation that owns the collection, which is on display in Berlin’s Museum of Decorative Arts, argued the case did not belong in American courts.

In this Jan. 9, 2014, a medieval Cross, part of the Welfenschatz, or Guelph Treasure, is displayed at the Bode Museum in Berlin. Ruling in a multi-million dollar dispute over a collection of medieval religious artworks, the Supreme Court made it harder Wednesday for certain lawsuits over property taken from Jews during the Nazi era to be brought in U.S. courts. The justices sided with Germany in a dispute involving the heirs of Jewish art dealers and the 1935 sale of a collection of Christian artwork called the Guelph Treasure. (Credit: Markus Schreiber/AP.)

Foreign nations generally cannot be sued in U.S. courts, although there are exceptions spelled out in the Foreign Sovereign Immunities Act.

“The heirs have not shown that the FSIA allows them to bring their claims against Germany. We cannot permit them to bypass its design,” Chief Justice John Roberts wrote in an opinion for a unanimous court.

Germany argued that an exception permitting certain suits against foreign countries in the U.S. does not cover those countries’ disputes with their own citizens over property. The Supreme Court agreed.

Roberts wrote that Americans would be “surprised … if a court in Germany adjudicated claims by Americans that they were entitled to hundreds of millions of dollars because of human rights violations committed by the United States Government years ago.” He said Germans’ reaction to this case might be expected to be the same.

In a statement, Hermann Parzinger, the president of the Prussian Cultural Heritage Foundation that owns the collection, welcomed the decision. He said it was the foundation’s “long-held belief that this case should not be heard in U.S. court.”

Nick O’Donnell, who represented the heirs of the art dealers, said in a statement that his clients were “obviously disappointed.” The case now goes back to a lower court for additional arguments on remaining issues, and O’Donnell said the heirs are considering their next steps.

Because of the decision in the Guelph Treasure case, the justices also sent a different dispute involving a suit against Hungary back to a lower court for further consideration. That case was filed in 2010 by 14 survivors of the Hungarian Holocaust, including some who survived being sent to the Auschwitz concentration camp. They are seeking to be compensated for property taken from them and their families when they were forced to board trains to concentration camps.

Both cases were argued in December. At the time, the Trump administration urged the justices to side with Germany and Hungary.

The cases are Hungary v. Simon, 18-1447, and Germany v. Philipp, 19-351.