Participants speak duringJeju Forum, an annual international conference on peace and security on Thursday. (Yonhap) JEJU — United Nations Secretary-General Antonio Guterres called Thursday for a renewed commitment to multilateralism and the principles of the UN Charter, as world leaders and policymakers gathered in South Korea for the opening of the Jeju Forum, an annual international conference on peace and security.In a video address to the opening ceremony, Guterres said this year's theme, "Reinventing Cooperation in a Fragmented World," reflects the need to strengthen international cooperation amid mounting geopolitical tensions.Reinventing cooperation means reaffirming our commitment to the UN Charter, he said. Multilateralism fit for today's realities must be more connected, more inclusive and more representative, he added.Guterres also praised the Jeju Forum for evolving into a platform that brings together diverse voices from across the international community rather than remaining confined to those of established powers.The 21st edition of the three-day forum opened Wednesday at Haevichi Hotel in Seogwipo, Jeju, drawing some 4,500 participants: current and former world leaders, senior officials from international organizations, diplomats, scholars and civil society representatives.In a separate video message, President Lee Jae Myung said South Korea would help address global challenges by serving as a "globally responsible nation.""The challenges facing the world today cannot be resolved by the efforts of just one or two countries," Lee said. "Countries with the capacity to solve problems must build flexible networks of cooperation to fill the gaps in the existing international order."Calling for greater efforts to build lasting peace, Lee added, "We must speak more actively about peace in order to create a world in which there is no need to fight." He said South Korea would use platforms such as the Jeju Forum to lead international cooperation for peace and prosperity.The forum is being jointly hosted by the Ministry of Foreign Affairs and Jeju Province for the first time, reflecting efforts to expand its role as South Korea's leading platform connecting central and local governments with the international community.Jeju Governor Oh Young-hun said the forum has grown beyond a regional event into a global platform for dialogue and cooperation."What we need today is not formal cooperation that repeats old approaches, but a new framework capable of solving shared challenges across borders, ideologies, generations and regions," said Oh.Slovenian President Natasa Pirc Musar also delivered a video address, urging middle powers such as South Korea and Slovenia to play a greater role in defending multilateralism, participating in minilateral partnerships and shaping governance for emerging technologies such as artificial intelligence.Indian External Affairs Minister Subrahmanyam Jaishankar, who delivered the keynote address in person, argued that fragmentation of the international order has become a structural reality rather than a temporary phenomenon.He proposed expanding cooperation through economic de-risking and supply chain diversification, building new partnerships among influential countries, upholding international law and norms, strengthening the Global South and reforming multilateral institutions.The forum runs through Friday with 68 sessions. Topics covered include the future of multilateralism, Middle East peace, Eurasian cooperation and a dialogue featuring prominent contenders to become the next UN secretary-general.