World leaders have been quick to condemn US President Donald Trump's decision to pull out of the landmark Paris climate agreement.
European leaders have also dispelled Mr Trump's assertion that the US's role in the accord will be renegotiated.
In a rare joint statement, continental Europe's three biggest economies - Germany, France and Italy - criticised his decision Thursday and said the pact was "not renegotiable."
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"We note the United States' decision with regret," the three countries said.
"We are firmly convinced that the agreement cannot be renegotiated."
In a separate press conference, French President Emmanuel Macron said Trump had "committed an error for the interests of his country, his people and a mistake for the future of our planet".
"I tell you firmly tonight: We will not renegotiate a less ambitious accord. There is no way," Macron said.
"Don't be mistaken on climate; there is no plan B because there is no planet B.
"I do respect this decision but I do think it is an actual mistake both for the US and for our planet.
"Wherever we live, whoever we are, we all share the same responsibility: make our planet great again."
European Commission President Jean-Claude Juncker also criticised the announcement, tweeting that the withdrawal was "a seriously wrong decision".
In Germany, a statement issued by seven Social Democratic ministers in Chancellor Angela Merkel's left-right coalition government said the United States "is harming itself, we Europeans and all the people of the world".
In response to the announcement, the European Commission pledged continued "global leadership in the fight against climate change".
Merkel says Paris accord an 'essential' pact
"The Paris Agreement will endure," it said in a statement issued by commissioner for climate action and energy Miguel Arias Canete.
"The world can continue to count on Europe for global leadership in the fight against climate change.... The EU deeply regrets the unilateral decision by the Trump administration."
Australia's Environment Minister Josh Frydenberg spoke with Prime Minister Malcolm Turnbull, who is in Singapore, following the announcement.
The pair have confirmed they still believe Australia's targets under the agreement are achievable.
Watch: 'US climate deal withdrawal is a mistake': Macron
"Donald Trump's announcement today is obviously very significant but Australia will carry on because as our prime minister has made very clear, when we sign up to international agreements ...we will follow through," Mr Frydenberg told ABC TV on Friday.
"Even without the US, around 70 per cent of the world's emissions are covered by that agreement."
A spokesman for UN Secretary-General Antonio Guterres said the decision to exit the Paris accord was a "major disappointment" and that Amercia needed to remain a "leader on environmental issues".
Watch: UN's 'major disappointment' on US climate pact decision
The spokesman, Stephane Dujarric, also said Guterres remained confident that US cities, states and businesses would "continue to demonstrate vision and leadership" by working for a low-carbon future.
"The decision by the United States to withdraw from the Paris Agreement on climate change is a major disappointment for global efforts to reduce greenhouse gas emissions and promote global security," the spokesman said in a statement.
"It is crucial that the United States remains a leader on environmental issues.
"The Secretary-General looks forward to engaging with the American government and all actors in the United States and around the world to build the sustainable future on which our grandchildren depend."
Trump has also come in for criticism from his predecessor, Barack Obama, who signed the deal in 2015.
He slammed the decision to withdraw saying the move would see the United States "reject the future".
"The nations that remain in the Paris Agreement will be the nations that reap the benefits in jobs and industries created," Obama said in a statement.
"Even in the absence of American leadership; even as this administration joins a small handful of nations that reject the future; I'm confident that our states, cities, and businesses will step up and do even more to lead the way, and help protect for future generations the one planet we've got."
Before leaving office, Obama helped shepherd the landmark international pact that commits all signatory nations to limiting global warming caused by carbon emissions.
"It was bold American ambition that encouraged dozens of other nations to set their sights higher as well," Obama said.
"And what made that leadership and ambition possible was America's private innovation and public investment in growing industries like wind and solar."
Watch: Canada slams US climate pact decision
Obama's former vice president, Joe Biden, also criticised the deal, tweeting that the decision to withdraw "imperils US security and our ability to own the clean energy future".
But Trump, who campaigned on a pledge to cancel US participation in the deal, said he would ditch the Paris accord because it handicaps the US economy.
"The Paris accord would undermine our economy, hamstring our workers, weaken our sovereignty, impose unacceptable legal risk, and put us as a permanent disadvantage to the other countries of the world," Trump said in a speech in the White House Rose Garden.
Trump said though that he was open to renegotiating the deal, or creating a new agreement, "on terms that are fair to the United States, its businesses, its workers, its people, its taxpayers".
