Russian President Vladimir Putin visited Tokyo this week for the first time in five years for a summit meeting with Prime Minister Junichiro Koizumi. They and their ministers signed 12 documents, ranging from joint efforts to counter international terrorism to economic cooperation, including a Russian promise to build an oil pipeline from eastern Siberia to the Sea of Japan coast.

But the two leaders failed to make a breakthrough in the Northern Territories dispute, preventing the summit from producing a joint statement. The Northern Territories consist of four islands -- Etorofu, Kunashiri and Shikotan islands, and the Habomai islets -- that Soviet forces seized in an operation that started on Aug. 18, 1945, three days after Japan's surrender, and continued to early September that year. The islands have been occupied since by Russians.

In the summit, Mr. Koizumi called on Mr. Putin to confirm the existence and validity of past agreements such as the 1956 Japan-Soviet Joint Declaration and the 1993 Tokyo Declaration. Japan believes the territorial talks should proceed on the basis of these agreements. In the 1956 joint declaration, the Soviet Union agreed to hand Shikotan Island and the Habomai islets over to Japan after the two countries sign a peace treaty. The 1993 declaration, signed by Prime Minister Morihiro Hosokawa and Russian President Boris Yeltsin, confirmed that territorial negotiations should cover the four islands and should be based on past documents jointly made by the two nations -- including the 1956 joint declaration, according to Mr. Yeltsin -- and on the principle of law and justice.