World leaders react with anger and defiance after President Donald Trump announced that the United States, the world's second biggest carbon emitter, was quitting the 2015 Paris climate agreement.
Led by Germany's Angela Merkel and France's Emmanuel Macron, they branded Trump's decision as misguided and vowed to defend an accord they portrayed as crucial for the future of the planet.
Leading greenhouse gas emitter Beijing on Friday promised to uphold the pact while European Commission chief Jean-Claude Juncker said there could be "no backsliding" on the deal.
In an exceptional step, continental Europe's three biggest economies -- Germany, France and Italy -- issued a joint statement criticising Trump's move and brushing off his offer of renegotiating the deal.
"We note the United States' decision with regret," they said, describing the carbon-curbing accord as "a vital tool for our planet, our societies and our economies."
On Friday in Brussels, Juncker opened trade and climate talks with Chinese Premier Li Keqiang with a promise to stick to the agreement, which aims to limit global temperature rises.
"Our joint leadership... makes a statement to the world: there is no reverse gear to the energy transition, there is no backsliding on the Paris agreement," Juncker said.
A foreign ministry spokeswoman in Beijing said China planned to "earnestly implement" its obligations agreed in Paris.
The United Nations said America's exit from Paris was a "major disappointment", with a spokesman for Secretary-General Antonio Guterres urging the US to remain a "leader on environmental issues".
Leaders of industry and business groups distanced themselves from the White House in the wake of Trump's decision.
Tesla founder Elon Musk confirmed he would quit White House advisory councils on business in protest, while Disney chief Robert Inger said he was resigning from the panels "as a matter of principle".
In his first ever tweet, Goldman Sachs CEO Lloyd Blankfein called the decision a "setback" for the environment and for US global leadership.
And former New York mayor Michael Bloomberg said he had offered $15 million to UN efforts to tackle climate change.
Merkel on Friday vowed "more decisive action than ever" to protect the climate.
"We in Germany, in Europe and the world will band together to take more decisive action than ever to confront and successfully surmount major challenges to humanity such as climate change," she told reporters.
In France, the presidential palace said Macron had phoned Trump to say that "nothing was negotiable" in the Paris agreement.
France and the United States "would continue to work together," but not on climate change, it said.
In a TV broadcast both in French and English, Macron cheekily adapted the nationalist slogan used by Trump on the campaign trail by urging climate defenders to "make our planet great again".
French former foreign minister Laurent Fabius, who helped broker the 2015 accord, said Trump's decision was "shameful" and a "major error".
Canadian Prime Minister Justin Trudeau called Trump to express his disappointment, but said he was inspired by "the growing momentum around the world to combat climate change and transition to clean growth economies".
Mexican ministers said the world had a "moral imperative" to live up to the Paris commitments, while Brazil's foreign ministry said it was concerned and disappointed by Washington's move.
Venezuela and Argentina also denounced the decision.
In unusually strong comments, Japanese Environment Minister Koichi Yamamoto said: "It's as if they've turned their back on the wisdom of humanity.
"In addition to being disappointed, I'm also angry."
Poor countries and island states at high risk of climate change effects such as rising sea levels have asked major emitters to do more to halt global temperature rises.
Tuvalu Prime Minister Enele Sopoaga accused Washington of turning its back on his country in its time of need, despite their alliance during World War II.
"We provided our islands as a launching pad for them to achieve their objectives and now we are facing the biggest war of our time, they are abandoning us," he said during a visit to neighbouring Fiji.