The foreign ministers of South Korea, China and Japan will meet for the first time in three years this weekend after bitter disputes over history and territory drastically scaled back high-level contacts and even raised security fears.
Anti-Japan sentiment in South Korea and China has grown sharply in recent years over what they see as Japan's growing nationalism and its push to obscure its brutal colonization of the Korean Peninsula and invasion of China in the first half of the 20th century. The annual trilateral talks have been subsequently suspended since they were last held in China in April 2012.
The political fights are a source of concern for the U.S., which wants to solidify its alliances with key allies South Korea and Japan to better deal with a rising China and growing nuclear threats from North Korea.
No major breakthrough is expected from Saturday's meeting, but analysts say the fact the talks are back on track is a meaningful step toward easing tension.
When the foreign ministers met in the past, a leaders' summit usually quickly followed but no such announcement is expected this time. Analysts say the resumption of the summit talks is crucial in prompting more high-profile bilateral talks where contentious issues can be discussed.
South Korea and China are expected to demand that Japan soften its position on history issues, and how Japan reacts will determine the fate for any leaders' summit, said analyst Lee Dae-woo at the private Sejong Institute in South Korea.
South Korea's President Park Geun-hye has never held official one-on-one talks with Japanese Prime Minister Shinzo Abe, while Chinese leader Xi Jinping held his first direct talks with Abe last November on the sidelines of a regional conference that Beijing hosted. The three leaders took office between late 2012 and early 2013.
At the centre of the Beijing-Tokyo spat is a cluster of East China Sea islands, which is controlled by Japan but claimed by Beijing. Japan's nationalization of the islands in 2012 sparked anti-Japanese riots and China then sent patrol ships to repeatedly enter the surrounding waters to confront Japanese coast guard vessels.
Abe's 2013 visit to a shrine where some war criminals are honoured incensed China and South Korea. Other thorny issues included Japan's reinterpretation of its war-renouncing constitution and an alleged attempt to undermine its past apology for forcing Asian women to provide sex to Japanese soldiers at wartime military brothels.
Despite their harsh history, the three countries are closely linked economically, with China the biggest trading partner for both South Korea and Japan. They are also members of now-stalled regional disarmament talks aimed at ending North Korea's nuclear weapons programs.
South Korea and Japan are both important U.S. allies that host tens of thousands of American troops, while China is the main backer of South Korea's chief rival, North Korea.
Abe, Park and Xi all plan to visit the U.S. this year.