JAKARTA -- South Korean President Moon Jae-in left for Vietnam on Friday, wrapping up his three-day state visit to Indonesia.

The South Korean leader was due in Da Nang, Vietnam later in the day for the start of the annual Asia-Pacific Economic Cooperation summit. It will be the second leg in his three-nation Southeast Asia trip that began on Wednesday.

His trip to Indonesia marked the first time he made a state visit to a foreign nation since taking office in May.

In a bilateral summit held Thursday, Moon and his Indonesian counterpart Joko Widodo agreed to further upgrade the countries' diplomatic relations to a "special strategic partnership" that will emphasize greater economic and trade cooperation, as well as exchanges between their people.

"The Special Strategic Partnership places greater emphasis on concrete cooperation for the benefit of the two countries and peoples in various fields, particularly in key industries and infrastructures, and on strengthening the two countries' contribution to the region and the world, especially through their joint efforts including triangular cooperation framework," they said in a joint statement issued after their bilateral summit.

Efforts to boost exchange between their people will include simplifying Seoul's visa issuance procedure for Indonesian tourists to South Korea.

Moon's trip to the region also came amid efforts to greatly improve South Korea's relations with the Association of Southeast Asian Nations.

Under what he calls the "New South Policy," the South Korean leader said his country seeks to build a win-win relationship with all 10 members of ASEAN.

Kim Hyun-chul, a senior economic adviser to Moon, earlier said the mutually beneficial policy will require Seoul to boost its imports from the countries to ensure joint development and co-prosperity.

"South Korea must expand its imports of agricultural goods or resources from ASEAN countries in the future," he said.

Moon's trip to the Southeast Asian countries also aims to win their support for Seoul's move to put more pressure on North Korea.

Pyongyang staged its sixth and most powerful nuclear test so far on Sept. 3.

The South Korean president insists maximum pressure and sanctions will leave the impoverished North with no choice but to come to the dialogue table and discuss a peaceful end to its nuclear ambition.

The APEC summit will bring together the leaders of 21 member economies, including the United States, Japan and China.

On Sunday, Moon will head to Manila for the East Asia Summit and a series of ASEAN forums that will also be attended by the leaders of China and Japan. (Yonhap)