The Japanese government has summoned Russia's ambassador to Tokyo to express "extreme regret" over a visit by Prime Minister Dmitry Medevedev to a chain of Russian-controlled islands that are also claimed by Japan.
Japanese Foreign Minister Koichiro Gemba said on July 3 that the visit to the Kuriles “pours cold water" on Russia-Japan relations.
Ahead of his arrival earlier the same day on Kunashir Island, Medvedev called the Southern Kuriles "an important part of the Russian land."
Speaking at a government meeting on Sakhalin Island, Medvedev also warned that ceding territory leads to the disintegration of a state.
"Those who gave away even a small patch of land usually sowed a storm. All of this ends in the collapse of a state," he said in televised remarks. "This is a very dangerous thing."
The Russian prime minister also pledged to improve the lives of the Kurile residents, many of whom eke out a threadbare living on the windswept chain.
"The farthest region of our state cannot and should not be the most deprived region although this was virtually the case some time ago," Medvedev said.
In November 2010, when he was president, Medvedev became the first Russian president to visit the island chain
. The islands, home to some 19,000 people, are rich in gold and silver and lie in waters abundant in marine life.
Tokyo claims the chain's four southernmost islands, known as the Northern Territories in Japan. The two countries' dispute over ownership continues to cast a cloud over Russian-Japanese relations and complicate investment and trade.
Tensions surrounding the Kuriles soared upon Medvedev's first visit two years ago, with Moscow saying in February 2011 that it would boost military defenses on the islands.
However, the dispute slackened somewhat after the earthquake and ensuing nuclear accident that shook Japan in March 2011 and prompted expressions of solidarity in Russia.
Russia and Japan have yet to sign a World War II peace treaty due to Tokyo's ownership claim.
Moscow seized control of the islands at the end of the war.
Based on reporting by AFP, Interfax, and ITAR-TASS