AFP - President Joe Biden opened on Thursday a summit of world leaders on the climate assuring that the United States "will not wait" to address the fight against global warming, which he considered a "moral and economic imperative."

The US president also praised the "extraordinary economic opportunity" linked to the fight against climate change, in a virtual meeting on Earth Day that brings together some 40 leaders by videoconference and will last two days.

The United States plans to double its official aid to developing countries to cope with climate change by 2024, compared to levels 10 years earlier, Biden announced.

"To help them achieve that goal, the United States will double ... by 2024 our annual development of public climate finance for developing countries," the president said during a summit of world leaders on climate sponsored by the House. White.

British Prime Minister Boris Johnson, who will host a major UN meeting on climate this year, praised the ambitious goal announced by the United States to fight global warming.