In a visit that left Japan seething, Russian Prime Minister Dmitry Medvedev traveled Tuesday to a disputed Pacific island and pledged to boost financing for four impoverished islands whose ownership has been disputed by Tokyo since World War II.
Russia captured the Southern Kurils chain — that lie some 7,100 kilometers (4,400) miles from Moscow — in 1945, but Japan still claims it as its own. The dispute for nearly seven decades has prevented Moscow and Tokyo from signing a peace treaty to formally end their hostilities.
Surrounded by rich fishing waters, the islands are believed to have offshore hydrocarbon reserves, gold and silver deposits.
The Russian government said Medvedev arrived at Kunashir Island on Tuesday with a group of officials. In 2010, he became the first Russian leader to visit the chain, which Japan calls the Northern Territories.
During a meeting with local officials, Medvedev pledged to allocate more government funding for the construction of fisheries and roads on the islands.
"Our easternmost region cannot be the most deprived one," Medvedev said in televised remarks.
After the 1991 Soviet collapse, the island chain has suffered neglect and its population has plummeted. Many remaining residents took up poaching of fish and crustaceans that are then sold illegally to Japan, South Korea and China.
Japan protested the visit.
"Medvedev's visit to Kunashir pours cold water on our relations," Japanese Foreign Minister Koichiro Gemba was quoted by the Interfax news agency as saying Tuesday.
Although economic ties between Japan and Russia have grown, little progress has been made in resolving the island dispute, which remains a source of deep political tension and distrust.
Japan claims the Soviet troops took control of the islands illegally and has consistently called for their return as a precondition for fully improved ties.
Russia's foreign minister dismissed the criticism.
"We have to move toward a peace treaty, but not through renewed protests — whether reasonable or not," said Sergey Lavrov.
Russia in 2005 suggested it would cede two of the islands if Japan gave up its claim to the other two, but Japan rejected the idea. The islands lie as close as six miles (10 kilometers) from Japan's Hokkaido island, but are also near an undisputed Russian territory.