The barracks from the Nazi camp at Auschwitz were on a 20-year loan but it has expired, The Washington Post reported Thursday.
"It is our priority to keep the barracks in the exhibition," said Sara Bloomfield, the museum's director. "We are in negotiations with our Polish partners about how to do that."
If the museum loses the barracks, "the whole veracity of the place will go," said Martin Smith, a documentary filmmaker who helped craft the exhibition that includes the barracks.
Witold Dzielski, first secretary of the Polish Embassy, said he understands the museum's desire to keep the barracks.
"All the other issues are being solved pretty easily," he said, referring to various objects that have been returned or exchanged. "But in the case of the barracks, it is a particularly difficult situation. There was an agreement, and according to Polish law there is no way that the barracks cannot be returned."