Japan's Chief Cabinet Secretary Matsuno Hirokazu has said it's regrettable that Russia decided to suspend the implementation of a bilateral fishing agreement.
Matsuno made the comment at a news conference on Wednesday.
Russia's Foreign Ministry announced on Tuesday that it will suspend the implementation of a 1998 agreement that allows Japanese fishing boats to operate safely near four Russian-held islands claimed by Japan.
Russia controls the islands. Japan claims them. The Japanese government maintains the islands are an inherent part of Japan's territory. It says the islands were illegally occupied after World War Two.
Matsuno said Moscow has made Japan's cooperation on other projects in the Sakhalin region as an apparent precondition to implementing the fishing agreement.
He said the government will continue consultations with Russia so that Japanese fishery workers can operate safely under the agreement.