US President Joe Biden has told world leaders at the annual UN General Assembly in New York that they must stand together against Russia.
"We have to stand up to this naked aggression today and deter other would-be aggressors tomorrow," he tells delegates.
On climate, President Biden says he's treating it as an existential threat, and the world needs to reduce its dependence on fossil fuels.
With so many important figures in one space, there is also an opportunity for leaders to hold meetings on the sidelines.
But French President Emmanuel Macron, China's President Xi Jinping, Russian President Vladimir Putin and UK PM Rishi Sunak are not there.