During his bilateral meeting with South Korea President Moon Jae-in on Monday, Duterte said he was hopeful that South Korean investors would pour in more investments in manufacturing, automotive, food production and processing, agribusiness, electronics and energy.
Meeting for the first time since their modus vivendi to put aside their differences and end a year-long standoff over the deployment of a USA missile defense system in South Korea, Presidents Moon and Xi reaffirmed their joint resolve to mend ties and restore cooperation in all areas.
The situation on the Korean peninsula dominated discussions at the Asia-Pacific Economic Cooperation summit in the central Vietnamese city of Da Nang. Mr Abe and Mr Moon did not meet for bilateral talks even though both attended summit meetings in Vietnam and the Philippines. China earlier had protested the installation of the system known as Thaad - which Seoul insists is for defensive purposes only against Pyongyang - and taken steps to punish it economically. Xi told Moon that he encouraged South Korea to resume dialogue with North Korea and re-engage with them for reconciliation and de-nuclearisation, state news agency Xinhua reported.
The leaders "shared the view on the need to stably manage the current security conditions on the Korean peninsula in relation to North Korea's nuclear and missile programmes, and agreed to seek to peacefully resolve the North Korean nuclear issue through dialogue", the office said.
The growing threat of North Korea's nuclear development in the region is also the leaders' agenda. "President Xi's reputation is on the line here", said Kim Jun-hyeong, a professor at Handong Global University.
"Prime Minister Medvedev said his country was willing to work closely with the South Korean side for the Korea-EAEU FTA", Yoon said in a press release, adding the Russian prime minister also expressed hope for increased cooperation between the two countries in the fishery and agriculture sectors.
China is South Korea's largest trading partner, buying about a quarter of the country's exports.
Journalists were only allowed to cover the two leaders' opening remarks. But his proposal that they pay mutual visits next year - the 40th anniversary of a friendship treaty between them - was met only with references to the importance of high-level exchanges, he told reporters. Mr Abe, on the other hand, has yet to visit China despite having been prime minister since 2012.
Amid the thawing relations, Japan-South Korea ties remain a sticking point. A banquet given for Trump featured a menu of shrimp caught in territory disputed with Japan, while the USA president was also introduced to a former victim of the trafficking of women to Japanese imperial army brothels before and during World War Two.
Abe said cooperation is vital to make the world economy more predictable, to mitigate vulnerabilities and to strengthen the free trade system. "I want to use all opportunities for dialogue because our two countries have great responsibility for the peace, stability and prosperity of the region and the world".