China and the US crossed swords Saturday ahead of an APEC summit, duelling over protectionism, trade tariffs and "chequebook diplomacy" as they laid out sharply contrasting visions for the Pacific Rim region.
The feisty exchanges laid the ground for what could be a fiery encounter between the Chinese leader and President Donald Trump at next month's G20 in Argentina.
Xi lashed out at "America First" trade protectionism and stressed that global trade rules should not be applied "with double standards or selfish agendas" -- in a thinly veiled swipe at Washington.
The world's top two economies have been embroiled in a spiralling trade war, imposing tit-for-tat tariffs on each other's goods in a confrontation experts warn could torpedo the global economy.
Xi urged the world to "say no to protectionism and unilateralism", warning it was a "short-sighted approach" that was "doomed to failure".
For his part, Pence vowed US tariffs would remain in place unless Beijing "changes its ways".
"We've put tariffs on $250 billion in Chinese goods and that number could more than double," he told CEOs from around the region.
Amid fears diplomatic and trade friction could spill over into the military sphere, Pence announced the US would join forces with Australia in the development of a new naval base.
And in a move likely to irritate Beijing, he also briefly met Taiwan's APEC representative.
Trump decided to skip the summit in Papua New Guinea, leaving the door open for Xi, who arrived two days earlier for a state visit and has been the undoubted star of the show.
Xi opened a new road and a school in Port Moresby, where he was serenaded by dozens of people from various tribes sporting parrot feathers, possum pelts and seashell necklaces.