Japan and Mongolia have drawn closer in recent years, with aid from Tokyo helping to spur economic development in the vast, sparsely populated country.

Emperor Naruhito and his wife, Empress Masako, are on an eight-day state visit to mark the 80th anniversary of the end of the war, during which Japan waged conflict across East Asia.

Japan did not invade Mongolia -- then a client state of the Soviet Union -- during its expansion into continental Asia during World War II.

But Moscow transferred thousands of Japanese prisoners of war to Mongolia after the end of the conflict, where around 1,700 are believed to have died while labouring on infrastructure projects.

On Tuesday, the couple laid flowers and held a minute's silence at a Tokyo-funded memorial at the site of a former cemetery for deceased prisoners of war in Dambadarjaa, near the Mongolian capital Ulaanbaatar.

At a banquet hosted by Mongolian President Ukhnaa Khurelsukh, Naruhito hailed the two countries' "deep friendship and cooperation".

"I hope the younger generation... will inherit the path of their predecessors and let blossom the many seeds of cooperation planted in this wide land," the emperor said.

He also teamed up with the Mongolian State Morin Khuur Symphony Orchestra to perform two songs on his viola.

The imperial couple are scheduled to attend the opening ceremony of Mongolia's biggest annual festival, Naadam, on Friday ahead of their departure on Sunday.

Also on Tuesday, they attended a welcome ceremony in Ulaanbaatar and reviewed a Mongolian honour guard.

Naruhito told reporters last week he hoped the visit would help to "invigorate exchanges further, particularly among the younger generation".

Tokyo's military legacy continues to colour its ties with other regional neighbours, particularly China and the Koreas.

The imperial couple have made several domestic trips this year to commemorate the war dead, including to Hiroshima, Okinawa and Iwo Jima.

Beijing said last month it would hold a grand military parade in September to mark the 80th anniversary of what it officially calls the War of Resistance Against Japanese Aggression and the World Anti-Fascist War.