A high school in Osaka Prefecture has canceled a student exchange program with its U.S. sister city following a disagreement over funds to maintain a memorial dedicated to women forced by the Japanese military into wartime sexual servitude.

The school in Higashiosaka had been planning to send six students to Glendale, California, for a home stay and exchange with local high school students for two to three weeks. In canceling the plan the school said its students could be at risk.

Nisshin Senior High School has been sending students to Glendale every year since 1996. It is the only sister-city exchange program between the two cities, according to the local board of education.

In July, Higashiosaka officials sent a letter of protest to Glendale after it posted a statement on its website that said each of its sister cities has "expressed an interest in developing a monument or memorial" within the park space, where a bronze statue of a woman in traditional Korean clothing was installed as a representation of Korean females forced into being "comfort women" by the Imperial Japanese forces.

The statement also said a maintenance fund will be established to cover the cost of any general maintenance and any vandalism or graffiti removal, and the fund will ensure that all maintenance costs related to sister-city monuments or memorials are covered by Glendale's sister-city partners.

Higashiosaka Mayor Yoshikazu Noda said in the protest letter that his city has never expressed such interest, nor has it given any consent to shoulder the expenses for the establishment of the fund.