US President Joe Biden and his Chinese counterpart, Xi Jinping, began their first face-to-face meeting as top leaders today as relations between the superpowers have reached their lowest point in half a century, amid deepening tensions over Taiwan, technology, the war in Ukraine and starkly divergent visions of the global order.

The summit in Indonesia, on the eve of a gathering of Group of 20 leaders, comes months after the United States imposed trade restrictions designed to hobble China’s ability to produce the most advanced computer chips.

Biden has cast China as a strategic adversary with “the intent to reshape the international order,” while Xi has warned of an increasingly perilous world in which unnamed foes — implicitly, the United States and its allies — aim to “exert maximum pressure on China.”