South Korean President Lee Jae-myung on Friday kicked off the Asia-Pacific Economic Cooperation (Apec) leaders' summit in the city of Gyeongju by warning that the region was at a critical inflection point with a rapidly changing global economic order.

President Xi Jinping and US Treasury Secretary Scott Bessent joined the annual summit of the grouping, a non-binding 21-member forum.

The Apec region accounts for 50 percent of global trade and 61 percent of GDP, and this year's meeting follows Xi's high-profile meeting with US President Donald Trump to find a trade war truce on the sidelines of the gathering in South Korea.

"It is clear we cannot always be on the same side, but we must work together to achieve common prosperity," Lee said.

"As the free trade order undergoes dramatic changes, global economic uncertainty is deepening and trade and investment are losing momentum," Lee added, noting cooperation among Apec members was a "clear solution" to the current economic challenges.

Guided by the theme "Building a Sustainable Tomorrow," this year's Apec agenda aims to advance regional connectivity, spur innovation-driven growth and create a more resilient future for the Asia-Pacific.

Established in 1989, APEC has become a dynamic engine of economic growth and one of the Asia Pacific's most important regional forums.

Trump described the meeting as a roaring success, saying he would cut tariffs on China, while Beijing had agreed to allow the export of rare earth elements and start buying American soybeans.

Their deals were a relief to the world economy, as experts previously warned that a failure to dial down trade tensions between the world’s two largest economies were certain to deepen global economic uncertainties.

Trump left South Korea after Thursday's meeting, and international media spotlight is now on Xi, whose government has portrayed itself as a defender of free trade and an alternative to US protectionism.

It’s Xi’s first visit to South Korea in 11 years, and he’s scheduled to meet South Korean President Lee Jae-myung and new Japanese Prime Minister Sanae Takaichi separately on Friday. (Agencies)