President Dmitry Medvedev yesterday said the Kuril Islands were an important part of Russia and he planned a visit, sparking concern in Japan which claims part of the Pacific archipelago.

Mr Medvedev said he had been hoping to visit the islands – the southernmost four of which are claimed by Japan – on his current trip to the Far East region but the plan had been thwarted by bad weather.

“This is a very important region of our country,” Mr Medvedev told reporters in the main city of Russia’s volcanic Kamchatka peninsula just north of the contested islands.

He said the weather around the islands – which are often blighted by fog – was not suitable for flying at the moment.

“But we will do it, we will definitely go there in the nearest future,” he said, without specifying which of the islands in the Kuril chain he would visit.

The archipelago of some 56 islands cascades down from the tip of the Kamchatka peninsula towards Japan’s Hokkaido island.

The status of the southernmost four seized by Soviet troops from Japan in 1945 is a major problem in Moscow-Tokyo relations.

Japan’s Foreign Minister Seiji Maehara warned yesterday that a presidential visit to the islands would “severely hurt ties”, the Kyodo News agency reported.

Japan’s Chief Cabinet Secretary Yoshito Sengoku, the top government spokesman, said at a regular press conference: “We have communicated our country’s stance to the Russian side through various channels.”

Asked if Japan wanted Mr Medvedev to stay away from the islands, he said: “To sum it up, that’s correct.”

With tensions rising, Konstantin Kosachev, the head of the Russian lower house of Parliament’s foreign affairs committee, described the comments by the Japanese foreign minister as “harsh and inadequate”.

“The Kuril Islands are an integral part of Russia and discussions about them can only be acceptable if this thesis is accepted as the starting point,” he told the Interfax news agency.