The annual meeting is the first major multilateral trade gathering since US President Donald Trump's announcement of sweeping tariffs and more than half the 21 members of the bloc face new US import duties in excess of the 10 per cent minimum.
APEC warned on Thursday that exports from a region that accounts for around half of world trade will slow sharply this year, and barely grow at all, in the wake of US tariff announcements.
The sessions are held with a focus on fostering multilateral cooperation on economies and trade, while contentious reforms to the World Trade Organisation are also in the spotlight this year.
The Trump administration views the WTO as a body that has enabled China to gain an unfair export advantage and has recently moved to pause US funding to the institution.
"Big economies in APEC might have strong views on certain issues," a top diplomat from one of the member economies told Reuters, expressing scepticism over the adoption of a joint statement by the close of the two-day meeting.
"But, we never know," the diplomat said.
"The chairman really wants it," referring to South Korea's Minister for Trade Cheong In-kyo.
An official from a different country, also expressing doubt about member economies adopting a joint statement, said working-level negotiations were ongoing until late into the night on Thursday.
For many of the member economies, the attendance of US Trade Representative Jamieson Greer raised the stakes of the conference held on South Korea's Jeju Island, ahead of a leaders' summit scheduled later in the year.
On the first day, many, if not all, of the representatives had or sought a meeting with Greer, according to host country officials.
"Quite a lot of countries had planned to send deputy ministers but later decided to send their ministers after Ambassador Greer's attendance was confirmed," Cheong said.
Greer held talks with China's Vice Commerce Minister Li Chenggang, less than a week after their first face-to-face talks in Geneva on Saturday and Sunday, where they agreed to significantly lower tariffs for 90 days.
Greer also met the host country's Cheong, three weeks after Seoul and Washington held their opening round of trade talks; and Malaysian Trade Minister Tengku Zafrul Aziz, who expressed optimism after Thursday's meeting, his second one in two weeks.
Australia, Canada, Japan, Singapore and Russia are among countries whose trade chiefs did not attend the gathering.
In late February, a Group of 20 meeting of finance ministers and central bankers held in Cape Town failed to adopt a joint communique, after top officials from several countries, including the United States, skipped it.
The meeting concluded with a "chair's summary" issued by the host, which said participants "reiterated the commitment to resisting protectionism" and used several words the Trump administration has strongly objected to.
Cheong is scheduled to hold a briefing on the meeting outcome on Friday afternoon.
