US President Joe Biden called for collective action to tackle climate change, saying the global community has no choice but to act to confront the existential crisis of our time.

No country can resolve this crisis alone, Biden said as he kicked off the global climate summit with 40 world leaders.

All of us, especially those of us in the world's largest economies, must act. It is a moral imperative, an economic imperative. A moment of danger, but also a moment of extraordinary opportunity, Biden continued. 

Countries that have followed his administration's lead and invested in tackling climate change will make their economies more resilient and competitive, he said.

The Biden administration has pledged to cut U.S. greenhouse gas emissions by 50% -52% by 2030 - a new target it hopes will encourage other high-emission countries to increase their ambitions to tackle climate change.