China and Europe pledged on Friday to unite to save what German Chancellor Angela Merkel called "our Mother Earth", standing firmly against President Donald Trump's decision to take the United States out of the Paris climate change pact.
Trump's move was "a big mistake", said Donald Tusk, one of the European Union's top officials.
Other countries, including India, signalled their commitment to the accord. Russian President Vladimir Putin said that while the United States should have remained in the 2015 deal, he would not judge Trump.
Trump announced the withdrawal on Thursday, tapping into his "America First" campaign theme. He said participating in the pact would undermine the US economy, wipe out jobs, weaken national sovereignty and put his country at a permanent disadvantage.
Members of his administration, including Vice President Mike Pence and Environmental Protection Agency chief Scott Pruitt, said on Friday that the Paris deal put an extraordinary burden on the United States.
"It was a transfer of wealth from the most powerful economy in the world to other countries around the planet", Pence said on television.
There was a mix of dismay and anger across the world.
France said it would work with US states and cities to keep up the fight against climate change. The governors of New York, California and Washington State have announced creation of a "climate alliance" committed to the Paris goals.
Germany's powerful car industry said Europe would need to reassess its environmental standards to remain competitive after the "regrettable" US decision.
The World Meteorological Organisation estimated that US withdrawal from the emissions-cutting accord could add 0.3°C to global temperatures by the end of the century in a worst-case scenario.
Germany's Merkel, a pastor's daughter who is usually intensely private about her faith, said the accord was needed "to preserve our Creation".
"To everyone for whom the future of our planet is important, I say let's continue going down this path so we're successful for our Mother Earth", she said to applause from lawmakers.
In Paris, French President Emmanuel Macron turned Trump's "Make America Great Again" campaign slogan on its head, saying in a rare English-language statement that it was time to "make the planet great again".
China and Europe together
At a long-planned meeting on Friday between Chinese Premier Li Keqiang and European Union officials in Brussels, the leaders pledged full implementation of the Paris deal. They committed to cutting fossil fuels use, developing more green technology and raising funds to help poorer countries reduce emissions.
China, the world's largest polluter, has emerged as Europe's unlikely partner in this and other areas as Trump has isolated the United States on many issues.
Tusk said Europe was "stepping up our cooperation on climate change with China... We are convinced that yesterday's decision by the United States to leave the Paris Agreement is a big mistake."
Earlier, European Commission President Jean-Claude Juncker said: "There is no reverse gear to energy transition. There is no backsliding on the Paris Agreement."
The vast majority of scientists believe global warming is mainly the result of human activities including power generation, transport, agriculture and industry.
A small group of sceptics, some of them in the White House, believe the Paris pact threatened business.
Trump once called climate change a hoax. Pruitt declined to tell reporters at the White House whether Trump now believes it is real and threatens the country. Pruitt's own view, he said, is that human activity contributes to climate change, but measuring how much is "very challenging".
Secretary of State Rex Tillerson, former CEO of Exxon Mobil Corp, had supported staying in the pact. He said the United States will continue efforts to reduce its emissions.
"It was a policy decision and I think it's important that everyone recognise the United States has a terrific record on reducing our own greenhouse gas emissions," Tillerson told reporters.
A number of figures from US industry expressed their dismay at Trump's move.
Jeff Immelt, chief executive officer of US conglomerate General Electric, tweeted: "Climate change is real. Industry must now lead and not depend on government."
Tesla Inc CEO Elon Musk, and Walt Disney CEO Robert Iger said they would leave White House advisory councils after Trump's move.
German industry associations warned that Trump's decision would harm the global economy and lead to market distortions.
Germany's DIHK Chambers of Commerce and VDMA engineering industry group said US companies could gain short-term advantages by Trump's decision.
"Climate protection can be pushed forward in an effective and competition-friendly way only by all states," said DIHK President Eric Schweitzer.
Trump's top economic adviser, Gary Cohn, said on television the withdrawal would help keep US energy markets competitive, allowing for a potential for coal. But coal industry officials have said the sector hopes only to slow the economic bleeding that has come with a glut of cheaper and natural gas.
On Thursday, the Sierra Club, an environmental group, was scathing about Trump's endorsement of what he regards as clean coal. It tweeted: "Clean coal, you can find that next to the unicorns and leprechauns."