A rare Asian summit in Seoul, which has brought together the leaders of China, Japan and South Korea, is focused on regional security and trade. Also on the agenda is nuclear-armed North Korea.
Breakthroughs were not expected at Sunday's meeting, but the commentators noted the inclusion of Japan's Prime Minister Shinzo Abe, whose country has long been ostracized over wartime atrocities.
Economically, however, the three Asian nations are closely linked. And at a concluding press conference, Park said the leaders had agreed to work toward the conclusion of a 16-nation free trade area to be known as the Regional Comprehensive Economic Partnership (RCEP).
Beijing has been a key proponent of RCEP, which would create the world's biggest trade bloc of 3.4 billion people.
Dialogue had become urgent
Kim Soung-Chul, an international policy expert in Seoul, said getting dialogue "going again" had become urgent because of "many common issues" and pressures at home and abroad in each country.
A mechanism for annual trilateral meetings last resulted in a meeting in 2012.
China was represented on Sunday by Premier Li Keqiang, rather than its president Xi Jinping.
The host, South Korean President Park Geun-hye, had told Li on Saturday that she hoped China, as North Korea's only major ally, would continue to restrain the reclusive state.
More patience, urges China
Li called for more patience amid efforts to create a nuclear-free Korean Peninsula, according to Park's office.
Abe, noted for his reluctance to fully acknowledging early 20th century atrocities committed by former imperial Japan, said en route to Seoul that he expected a "frank exchange" of views.
Separate talks due on Monday between Park and Abe were only confirmed a few days ago amid reports of bickering over how Japan's former wartime sex slavery of Korean women might be rhetorically addressed.
Many South Koreans see his past remarks as falling short of a full apology.
Tokyo professor Hideshi Takesada said the so-called "comfort women" issue was unlikely to be resolved during the summit beyond agreeing to continue dialogue.
China has bitter memories stemming from past Japanese invasion and is also at odds with Tokyo over sovereignty of an East China Sea island chain.
Washington had also pushed South Korea and Japan to heal their rift.
About 80,000 US troops are hosted by Japan and South Korea, forming the core of America's military presence in the Asia-Pacific region.
Pentagon chief visits DMZ
US Defense Secretary Ashton Carter visited the Demilitarized Zone (DMZ) dividing the Korean Peninsula on Sunday and renewed calls for North Korea to cease "provocations" and to reduce its nuclear activities to "ultimately zero."
He later said that the US remains committed to six-party talks that seek the denuclearization of the peninsula.
ipj/ng (AP, AFP)