Japan's Prime Minister Shinzo Abe said he was willing to discuss a peace treaty with Russia -- two countries still technically at war with each other -- during a meeting with Vladimir Putin on Wednesday.
The two leaders met face-to-face on the sidelines of the regional Association of Southeast Asian Nations (ASEAN) summit in Singapore.
Both countries are seeking to try to end a thorny territorial row that has dogged relations since the end of World War II.
The dispute between Russia and Japan centres on four islands in the strategically-located Kuril chain which the Soviet Union occupied at the end of the war in 1945 but are claimed by Japan.
It has kept the two countries from signing a peace accord that would formally end their wartime hostilities.
"We hope to discuss not only bilateral cooperation, including our economies... but also the issue of the peace treaty," Abe told Putin, according to a Russian translation of his words at the start of the meeting.
"I am ready to give enough time to this, the peace treaty," he added.
Putin first suggested the two countries sign a peace treaty "without any preconditions" in September.
The proposal was initially received coolly in Japan, where a government spokesman said the two countries should first resolve the dispute before signing a peace deal.
But in recent months, diplomatic efforts to resolve the issue appear to have accelerated, at least to the point where Japan is willing to discuss what a treaty might look like.
In his response to Abe on Wednesday Putin said: "I am delighted to be able to discuss with you all the angles of our cooperation, including those that you personally consider to be priorities."
Historically, Japan insists the islands, which were once inhabited by the Ainu indigenous people, have never belonged to anyone else.
Russia considers them spoils of war as agreed between then US president Franklin Roosevelt and Soviet leader Joseph Stalin in 1945.
Strategically, control of the islands gives Russia year-round access to the Pacific Ocean for its Pacific fleet of warships and submarines based in Vladivostok, as the surrounding water does not freeze in winter.