They have arrived in Port Moresby for the Informal Senior Officials Meeting (ISOM).
The delegates visited the APEC Haus, National Parliament Haus and the International Conventional Centre.
The ISOM meeting will commence today (Dec 5) and ends on Wednesday (Dec 6).
The leaders are in Port Moresby to discuss priorities and key activities for the 2018 APEC, to be hosted by Papua New Guinea.
As Chair, Papua New Guinea will guide the next steps in APEC to boost economic integration and trade, and equip workers and businesses of all sizes, in all parts of the region, to confront profound changes underway in market competition, automation and skills demand.
Enabling infrastructure development, digitally driven trade and reforms in education, training and social safety nets will be among the policy issues on the table.
The aim is to improve business conditions, job prospects and wages needed to foster inclusive and sustainable growth.
About 200 delegations from the 21 APEC economies will be attending this meeting.