A museum in Los Alamos, New Mexico — a once-secret New Mexico city that developed the atomic bomb which helped end World War II — has put an exhibit from Japan on hold because of its theme of abolishing nuclear weapons.

The Los Alamos Historical Museum confirmed Monday that it will not host a traveling exhibit organized by the Hiroshima Peace Memorial Museum and Nagasaki Atomic Bomb Museum until all parties can work out their differences over the theme.

The exhibit, which features articles of clothing, exposed plates, and other personal items from victims, aims to draw attention to the horrors of the bombs that destroyed both cities.

Heather McClenahan, executive director of the Los Alamos Historical Museum, said the museum’s board of directors felt uncomfortable about the exhibit’s call to abolish nuclear bombs. The New Mexico city is still home to the Los Alamos National Laboratory, one of the nation’s premier nuclear weapons research centers.

The exhibit dispute comes as the Los Alamos National Lab competes with the U.S. Energy Department’s Savannah River Site in South Carolina to continue production of plutonium pits. Those are critical cores which trigger nuclear warheads.

No new pits have been made since 2011. The Energy Department wants to ramp up production to 80 pits a year by 2030.

“The Los Alamos Historical Society will continue its dialogue with the museums in Hiroshima and Nagasaki in hopes that we can overcome cultural and linguistic differences and host exhibits that are respectful to all of our communities’ concerns and stories,” McClenahan said. “In other words, we hope this is not the end but the beginning of delving together into our history and the questions it raises.”