SYDNEY, Australia — The United States and China turned a Pacific Rim trade summit this weekend into a stage where the world could do little more than stand by and watch as two great powers aggravated their battle over trade.

President Xi Jinping and Vice President Mike Pence both made their cases to the global leaders assembled in Papua New Guinea — then they dug in and refused to compromise. That left the group of 21 nations in disarray, unable to agree on even a routine joint statement like those that had closed every other Asia Pacific Economic Cooperation summit since 1989.

Countries caught in the trade-war crossfire between China and the United States are becoming increasingly exasperated.

“The entire world is worried,” said Prime Minister Peter O’Neill of Papua New Guinea.

The disagreement over the final statement reflects a hardening of the conflict between China and the United States, with each side deploying aggressive, uncompromising rhetoric reminiscent of that heard during the Cold War.