Chinese Premier Li Keqiang arrived in Seoul today for a three-way summit with South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe aimed at repairing relations strained from historical and territorial issues.
A day before the summit, Park and Li were set to hold a separate meeting today with a likely focus on trade issues between two of the region's closest economic partners.
Li might also seek some sort of assurance from Park that Seoul, a key US ally, will keep a neutral stance over the recent flare-up between Washington and Beijing over the US Navy's freedom of navigation operations in the disputed waters of the South China Sea, analysts said.
Tomorrow's trilateral summit will be the first since 2012.
The meetings were shelved after Japan's ties with its two neighbors deteriorated over disputes stemming from its wartime aggression and territorial claims.
Park will separately meet Abe on Monday in the first formal bilateral summit in more than three years.
Japan and China have been gradually resuming exchanges following 2012 tensions over the control of disputed islands in the East China Sea. The rift began healing after diplomats agreed to restart contacts last November, when Chinese President Xi Jinping briefly met and shook hands with Abe.
Park has met Xi six times since she took office in 2013, in efforts to further strengthen ties with China, South Korea's largest trade partner which also has unusual leverage with the hard-to-read, nuclear-armed North Korea.
However, Seoul's ties with Tokyo have been persistently icy after hawkish Abe came to power in December 2012, as the countries struggled to settle disputes stemming from Japan's brutal colonial rule of the Korean Peninsula in the early 20th century. China has similar gripes with Japan.
The US wants Japan and South Korea, important allies in the region, to be on better terms to counter China's growing geopolitical influence, including in the South China Sea, and also to strengthen security cooperation against North Korea.
The US Navy earlier this week sent a warship in its most direct challenge yet to China's artificial island building that has upset other claimants in the South China Sea, including the Philippines, a close US ally.
China claims nearly all of the South China Sea, but Washington says the waters are international territory and must be open for navigation.