President Yoon Suk-yeol left for Cambodia on Friday on the first leg of a two-nation tour that will include his attendance at various summits involving the Association of Southeast Asian Nations and the Group of 20.

In Phnom Penh, Yoon is scheduled to attend a South Korea-ASEAN summit, an ASEAN Plus Three summit and the East Asia Summit during a three-day stay, with other bilateral and multilateral meetings expected to take place on the sidelines.

Yoon told reporters earlier he will hold a trilateral summit with U.S. President Joe Biden and Japanese Prime Minister Fumio Kishida during the trip, the second of its kind following one on the sidelines of a North Atlantic Treaty Organization summit in Spain in June.

A presidential official said a bilateral meeting with Biden was also fixed, while no decision had been made on one with Kishida.

Yoon's first trip to Southeast Asia as president has also drawn attention because it sets the stage for his first meeting with Chinese President Xi Jinping, likely during the G-20 summit to be held in Bali, Indonesia, on Nov. 15 and 16.

A presidential official said the two are expected to meet "naturally" during the course of the events but that nothing had been predetermined in terms of format.

ASEAN, which comprises Brunei Darussalam, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam, is the fifth-largest economic bloc in the world and South Korea's second biggest trading partner.

The region is strategically important, as it is emerging as a global production hub, is rich in critical minerals and raw materials, and boasts a large consumer market, according to officials.

During the South Korea-ASEAN summit set for Friday, Yoon will unveil South Korea's new Indo-Pacific strategy for freedom, peace, and prosperity, and a new policy approach toward ASEAN, known as the "South Korea-ASEAN solidarity plan." He will then meet with South Korean residents in Cambodia together with first lady Kim Keon-hee, who is accompanying him on the trip.

On Saturday, Yoon plans to attend the ASEAN Plus Three summit, which involves ASEAN, South Korea, Japan, and China, and outline Seoul's plans to increase practical cooperation between ASEAN and the East Asian nations, before attending a gala dinner hosted by Cambodia, the current chair of ASEAN.

On Sunday, he will attend the East Asia Summit and outline South Korea's basic stance on regional and international issues, while also emphasizing its commitment to contributing to peace, freedom and prosperity, according to his office.

While in Cambodia, Yoon will hold separate summits with the leaders of Cambodia, Thailand and the Philippines.

On Sunday evening, he will depart for Bali ahead of the G-20 summit and attend various business events the next day, including a meeting with South Korean businesses in Indonesia, a South Korea-Indonesia business roundtable, and a B20 summit involving business groups and entrepreneurs from the G-20 nations.

On Tuesday, the last day of his tour, Yoon will attend the G-20 summit, give speeches during two sessions -- one on food, energy, and security, and another on health -- and attend a leaders' luncheon and welcome dinner before departing for Seoul late in the evening.

The president and first lady are scheduled to return to Seoul early Wednesday.