China, Japan and South Korea will this week hold the first meeting of their foreign ministers for three years, Tokyo said Tuesday, the latest sign of a gradual thaw in East Asian relations.

The three men will meet in Seoul on Saturday, a Japanese foreign ministry official said, the first time the countries' top diplomats have held talks since April 2012.

"Cooperation among the three countries is important for Japan and we naturally hope this foreign ministers' meeting will lead to a summit in the future," the official said.

No date had been set yet for a three-way summit, he added. Leaders from the three countries last met in May 2012.

Chinese foreign ministry spokesman Hong Lei confirmed the meeting, which he said would be an opportunity for set the tone for future relations.

"Foreign ministers of the three countries will review the progress made during trilateral cooperation and exchange views on the principles that should be held and the future direction of trilateral cooperation," he told reporters in Beijing.

While relations between China and South Korea are strong, both have strained ties with Japan, chiefly because of historical and territorial disputes.

Japan and China have long been at odds over the sovereignty of uninhabited islands in the East China Sea, which Japan administers and calls the Senkakus, but which China claims as the Diaoyus.

Relations soured further in 2012 when the Japanese government angered China by nationalising some of the islands.

Since then, Tokyo and Beijing have routinely clashed over the issue, with official Chinese ships and aircraft regularly testing Japanese forces.

Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping staged a frosty handshake on the sidelines of the Asia-Pacific Economic Cooperation forum in November, but ties remain under pressure.

South Korean President Park Geun-Hye has held two summits with Xi, but only sat down with Abe at a three-way summit under pressure from Washington.

- 'Strategic liability' -

Seoul-Tokyo ties have always been problematic, given the bitter legacy of Japan's 1910-45 rule over the Korean peninsula.

As well as a dispute over some South Korea-controlled islets, Seoul feels Tokyo has yet to fully atone for the excesses of its colonial past and the forced recruitment of South Korean women to wartime military brothels.

The friction is a source of irritation for Washington, which would rather its two key regional allies could bury the hatchet and instead focus on forming a united front against an increasingly assertive China.

US Assistant Secretary of State Daniel Russel, in Seoul Tuesday, said relationship difficulties needed to be ironed out for the good of everyone.

"We will work to support the improvement in bilateral relations between Japan and Korea," Russel said, adding that the US was friends with both nations.

"Tension between those two friends constitutes a strategic liability to all of us," he said.

He also urged the Asian players to deal with the "legacy of history in a way that creates progress for the 21st Century".

UN Secretary-General Ban Ki-moon, speaking in Tokyo to mark the 70th anniversary of the global body, on Monday called on leaders from the three countries to promote dialogue "in a forward-looking manner".

"I would urge leaders in the region to be future-oriented, remembering the past," he said.

"We should move forward in a spirit of cooperation for our mutual benefit to achieve common prosperity and shared goals."