An "inspection" of the Kuril Islands by Japan's foreign minister over the weekend brought a pensive reaction from Russia, which claims the disputed lands.

Japanese Foreign Minister Koichiro Gemba viewed the islands from a Japanese coast guard ship Saturday, the Kyodo News Agency reported.

Gemba paid his first visit as foreign minister to what Tokyo calls the Northern Territories -- four Pacific islands that were occupied by Soviet troops at the end of World War II and which Moscow has claimed since.

The visit prompted a statement from Russia's foreign ministry saying it hoped Tokyo wasn't using the event to draw attention to its claims over the chain of islets stretching north from Japan's northernmost island of Hokkaido.

The incident came as the countries have pledged to strengthen ties despite the Kuril Islands dispute, which prevented Japan and the Soviet Union from signing a peace treaty following World War II.

Gemba made the visit ahead of an anticipated trip by Russian Foreign Minister Sergei Lavrov to Japan, possibly this month.

The Japanese foreign minister expressed solidarity with one-time island residents and their families, many of whom are living in the Hokkaido city of Nemuro after being deported in the late 1940s by Soviet occupiers.

"The former islanders are aging," Gemba told Kyodo. "I think this issue will have to be resolved as quickly as possible."

Russia, however, has consistently upheld its sovereignty over the islands, which has a community of 30,000 Russian residents and a military presence.

Russian President Dmitry Medvedev paid the first visit by a Russian head of state to the Kurils in November 2010, four years after Moscow instituted a $630 million plan to develop the island chain.

In December the Russian Federal Agency for Special Construction announced it would build military posts on the islands of islands of Iturup and Kunashir starting in 2013, at a cost of $377 million, the Russian news agency RIA Novosti said.

A civilian-military airfield in the Kurils is also being renovated.

Gemba's "inspection" of the islands prompted Moscow to issue a statement Saturday saying the episode had the feeling of a reassertion of Japan's sovereignty over the disputed area, the Chinese news agency Xinhua reported.

"The Russian Ministry of Foreign Affairs has paid attention to the so-called 'inspection' of the South Kuril Islands by Japanese Foreign Minister Koichiro Gemba on Jan. 14 from a Japan coast guard ship that was sailing in Japanese territorial waters," the statement said.

"We would like to know if this move was intended to emphasize the importance of mutually beneficial cooperation between border areas of Russia and Japan and thereby give an extra impulse to the sustained development of Russian-Japanese ties," the statement said.

But, it warned that if the "inspection" was indeed meant to press Japan's claims over the Kurils, it won't help long-term bilateral relations between the countries.

The importance of strengthening those ties was highlighted last month with the death of North Korean leader Kim Jong Il and his succession by his son Kim Jong Un.

Gemba and Lavrov agreed to the work together to maintain stability on the Korean Peninsula during the transition period in North Korea, as well as to help resolve the issue of Japanese nationals abducted by Pyongyang regime, Kyodo reported.