On 4 September 2023, Mr. Sarun Charoensuwan, Permanent Secretary for Foreign Affairs, witnessed the signing ceremony of the Instrument of Accession to the Treaty of Amity and Cooperation in Southeast Asia (TAC) by Serbia, Panama, and Kuwait, adding up High Contracting Parties to the TAC to 54 States/Organisations.
Later on, PS Sarun also witnessed the signing ceremony of the Secretariat-to-Secretariat Memorandum of Understanding (MoUs) between ASEAN and the Indian Ocean Rim Association (IORA) and Between ASEAN and the Pacific Islands Forum (PIF) at the ASEAN Secretariat, Jakarta, Indonesia.