From food and energy insecurity to the Sino-U.S. rivalry and the war in Ukraine, Group of 20 leaders will have their work cut out for them when they meet next Tuesday and Wednesday for a summit that is seen as a test for global leadership.

A series of potential face-to-face meetings on the sidelines of the forum — which will bring together leaders from the world’s leading rich and developing countries in Bali, Indonesia — will be of particular importance. That includes an in-person meeting between U.S. President Joe Biden and his Chinese counterpart Xi Jinping, as well as a possible meeting between Xi and Prime Minister Fumio Kishida.

Topping the agenda at the G20 summit, which will be one of three major international gatherings in Southeast Asia over the coming days, will be the war in Ukraine, in particular concerns about nuclear weapons as the Kremlin threatens to use “all available means” to overcome battlefield losses.