Japan's premier Wednesday said his country's relationship with China must move away from an "excessive focus" on the past during a meeting with a top Beijing envoy.

Prime Minister Shinzo Abe made the remarks to State Councillor Yang Jiechi, the highest-ranking Chinese diplomat to make an official trip to Tokyo for several years, a senior Japanese government official said.

His visit signals a possible thaw between the world's second and third largest economies despite territorial disputes and tensions -- issues that continually dog diplomatic visits.

During the meeting Abe told Yang that "Japan has an unshakable history as a pacifist nation," and has learned lessons from its past, according to Hiroshige Seko, deputy chief cabinet secretary.

"We must build future-oriented Japan-China relations, rather than keeping an excessive focus on unfortunate past," Seko quoted the premier as telling the Chinese diplomat.

Relations between Japan and China -- long terse over Beijing's belief that Tokyo has yet to seriously atone for its wartime atrocities -- plunged in 2012 following Tokyo's nationalisation of disputed islands in the East China Sea.

Beijing also balks at Abe's regular visits to the controversial Yasukuni war shrine while the Communist party stokes Chinese nationalism as part of its claim to legitimacy.

More recently ties have improved, but there are still regular flare ups between the two nations.

Japan lashed out last week at UNESCO's decision to inscribe documents related to the Nanjing massacre in its Memory of the World register following a request from Beijing.

Tokyo has threatened to withdraw funding for the UN body over the row, while China criticised Japanese anger.

Abe "expressed that he regrets the registration of the Nanjing incident" and said improvement of public sentiments toward each other is a key to advancing the bilateral relations, according to Seko.

Yang reiterated China's "officially stated positions," Seko said.

The massacre, often referred to as the "Rape of Nanjing", was a period of mass murder and rape committed by Japanese troops after the fall of the Chinese city of Nanjing in 1937.

Despite the clear disagreements, Seko put a positive spin on the meeting, describing it as "warm and friendly," in line with attempts by Abe and Chinese leader Xi Jinping to gradually improve their relations.

Abe told Yang that Japan and China share responsibility to keep peace in the region, and voiced his wishes to meet with Chinese leaders at international meetings, such as G20, Seko said.

Yang supported Abe's views on regional stability and said he "took note" about Abe's enthusiasm in improving bilateral ties, Seko said.

On Tuesday evening China's state-run Xinhua news agency quoted Yang as saying Sino-Japanese ties had been improving.

"The Chinese government attaches great importance to China-Japan ties and is willing to maintain dialogue and contact with Japan," Yang was quoted as saying.

"China would like to cooperate closely with Japan to boost bilateral ties in a spirit of drawing lessons from history and facing up to the future," the Beijing envoy added, according to Xinhua.