Indonesian President Joko Widodo called on world leaders on Thursday to defuse tensions as they met at a Southeast Asian-hosted summit to focus on security and trade against a backdrop of intensifying big-power rivalries. U.S. Vice President Kamala Harris, Chinese Premier Li Qiang, and Russian Foreign Minister Sergei Lavrov joined the summit in the Indonesian capital led by the Association of Southeast Asian Nations (ASEAN), along with leaders of partner countries Japan, South Korea, India, Australia and others.