On July 3 Medvedev visited the Island with several senior government officials including the vice prime minister.

It was his second drop after the one made in November 2011 in his former capacity as the head of state.

Medvedev, going round commercial service facilities, underscored the need to keep pushing forward the socio-economic development plan of the southern Kurils, after learning about harbor construction.

Upon hearing the news, the authorities of the Japanese government including the chief Cabinet secretary blamed it as an act of throwing cold water on the recent positive atmosphere between the two countries, and the Japan Foreign Ministry summoned the Russian ambassador in Tokyo to lodge protest against it.

Commenting on this, the vice chairman of the International Affairs Committee of the Russian Federal Assembly in an interview strongly rejected it as an intolerable interference in the country's internal affairs. He asserted that the southern Kurils belong to Russia, urging Japanese politicians to recall their country's unconditional surrender in World War II.

As known, Japan and Russia have long been engaged in the territorial disputes over Etorofu, Kunashiri, Shikotan and Habomai, four islands of the Kurils.

As a result of World War II, the former Soviet Union grabbed the whole of the archipelago under the agreement of big powers on postwar handling of defeated countries. And Japan, in September 1951 officially declared at San Francisco conference that it gives up dominium over the archipelago.

Japan, however, denying this historical fact, has persistently claimed the Kurils raising unreasonable allegations that the archipelago mentioned in the San Francisco Peace Treaty did not include the disputed four islands.

Russia reiterated its stand never to compromise as regards the Kurils.

Medvedev, during his recent visit, pointed out that he "will not concede even an inch of the Russian territory", reaffirming his will to firmly maintain the country's territorial right over the four controversial islands.

He at a press conference in Kamchatka Territory on July 5, referring to Japan's feedback over his visit to Kunashiri Island, said with irony that "I have no interest in Japan's response. So I don't want to waste my time answering such questions."

Analysts expect Russian-Japanese stand-off and friction escalating again over the Kurils' issue will badly influence the overall bilateral relations.