Russian Defense Minister Sergei Shoigu on Monday ordered the speeding up of construction of military and civilian infrastructure on a chain of islands in the Pacific Ocean where Moscow and Tokyo have rival territorial claims.

Dispute over the islands has strained relations between the two countries since World War II, when Soviet forces occupied four islands at what Russia calls the southern end of the Kurile chain.

Shoigu was speaking in Russia's Far East city of Vladivostok while inspecting the eastern military district, his ministry said in a statement. It did not provide more detail.

Moscow has angered Tokyo in recent years by having state officials visit the island chain and stepping up military activities there. Japan says the islands are part of its territory and wants Moscow to hand them over.