A shipment of waste contaminated with PCB — polychlorinated biphenyls — from domestic U.S. military facilities will temporarily remain in Japan after returning to Yokohama today, the U.S. Embassy in Tokyo said Monday.

A cargo ship carrying the waste — about 100 tons of PCB-contaminated garbage from the U.S. Army supply depot in Sagamihara, Kanagawa Prefecture — will return to Japan after both Canada and the United States refused it entry.

The United States said the waste will be kept at an unspecified location in Japan until it is shipped out within a month, adding that it will not return to the facility in Sagamihara.

Vice Foreign Minister Yutaka Kawashima, speaking to reporters, urged that the U.S. ensure a “safe method” is employed to store the waste. and said Japan recognizes that the waste is only going to be stored here “temporarily.” Sagamihara and other municipalities had feared the waste would be returned to the U.S. military facility there.

The temporary destination of the waste was not made public, but a U.S. Embassy source said it could be stored at a U.S. military facility in Yokohama or Yokosuka because both sites are near Yokohama port.

The waste includes garbage contaminated by PCBs, which are used in transformers, as well as other U.S. military trash.

A cargo ship carrying the waste left Yokohama port on March 23 but headed back to Japan after dock workers’ protests stopped it from landing in Seattle on April 7, Japanese officials said.

The shipment was originally to be unloaded in Vancouver but local authorities refused to allow the cargo to be landed and sent it to Seattle.