Russian President Vladimir Putin and Japanese Prime Minister Shinzo Abe are due to meet in Moscow on May 26 to hold talks that are expected to focus on North Korea, the disputed Kurile Islands, and economic cooperation.
The meeting comes amid uncertainty about a summit between U.S. President Donald Trump and North Korean leader Kim Jong Un initially scheduled to take place in Singapore next month.
On May 25, the two leaders attended the St. Petersburg International Economic Forum 2018 and held talks with members of the Russian-Japanese business council.
In a speech at the forum, Abe underlined the importance of cooperation between Moscow and Tokyo in the denuclearization of North Korea.
Abe and Putin are also expected to decide on accelerating preparations for joint economic projects on the Russian-administered Kurile Islands, an archipelago also claimed by Japan, which calls them the Northern Territories.
The two leaders agreed in December 2016 to start consultations on joint projects on the islands, but little progress has been made in the mean time.
The Soviet Union occupied the islands at the end of World War II, forcing 17,000 Japanese inhabitants to leave.
Because of the territorial dispute, a formal peace treaty has yet to be signed between the two countries.