The United States and China have agreed to resume a working group on climate cooperation and pledged a major ramp-up of renewable energy, the two sides announced Wednesday ahead of a leaders’ summit in San Francisco, as the world’s two largest polluters seek to overcome their geopolitical tensions to tackle the climate crisis.

The announcement came hours before US President Joe Biden and Chinese leader Xi Jinping are set to sit down on the sidelines of the Asia-Pacific Economic Cooperation summit for their first talk in a year – a highly anticipated meeting aimed at stabilizing rocky relations.

Cooperation on climate change has long been seen as a rare bright spot in an otherwise difficult US-China relationship strained by tensions over trade, technology, human rights and geopolitics. But even that bright spot had dimmed over the past year, with Beijing cutting off climate talks with Washington in retaliation for a high-level US visit to Taiwan last summer.