President Donald Trump announced the United States is withdrawing from the Paris climate change accord.
Trump believes the Paris pact is a bad deal for American workers and was poorly negotiated by the Obama administration.
Speaking in the White House Rose Garden Thursday, Trump said, "This agreement is less about the climate and more about other countries obtaining a financial advantage over the United States."
The president said the agreement gives "countries an economic edge over the United States," adding, "that's not going to happen while I'm president."
He says that he is seeking to create a "level playing field" and establish the "highest standard of living, highest standard of environmental protection."
Trump adds, "I was elected to represent the citizens of Pittsburgh, not Paris."
In a joint statement ,France, Germany and Italy said the accord cannot be renegotiated.
French President Emmanuel Macron, German Chancellor Angela Merkel and Italian Premier Paolo Gentiloni said that they take note "with regret" the U.S. decision to pull out of the 2015 agreement.
The three leaders say they regard the accord as "a cornerstone in the cooperation between our countries, for effectively and timely tackling climate change."
They added that the course charted by the accord is "irreversible and we firmly believe that the Paris Agreement cannot be renegotiated."
Macron, Merkel and Gentiloni say they remain committed to the deal and will "step up efforts" to support the poorest and most threatened nations.
In a statement Thursday, mayors of the world's megacities committed to addressing climate change said that despite the U.S. move, American cities can continue to play a role in trying to prevent catastrophic global warming.
The mayor of Paris, Anne Hidalgo, says climate change "poses a unique threat to the future of our planet, and puts in peril the health, prosperity, security and the very survival of our children and grandchildren."
Hidalgo says she's urging the Trump administration to reconsider the decision.
Steve Adler, the mayor of Austin, Texas, said his city won't stop fighting climate change.
Former President Barack Obama says the Trump administration is joining "a small handful of nations that reject the future" by withdrawing from the Paris climate change pact.
Obama is defending the deal that his administration painstakingly negotiated. He says the countries that stay in the Paris deal will "reap the benefits in "jobs and industries created." He says the U.S. should be "at the front of the pack."
The former president says in a statement that Trump's decision reflects "the absence of American leadership." But Obama says he's confident nonetheless that U.S. cities, states and businesses will fill the void by taking the lead on protecting the climate.
Obama says that businesses have chosen "a low-carbon future" and are already investing heavily in renewable sources like wind and solar.
Speaking to reporters on Thursday, a spokesman for Russian President Vladimir Putin, Dmitry Peskov, said that Russia "thinks highly" of the accords and there is no alternative to it. But he added that its implementation will not be as effective "without the key signatories." Peskov said Russia has yet to see what announcement Trump makes.
Putin is meeting with Indian Prime Minister Narendra Modi later on Thursday. Modi on Wednesday expressed India's commitment to fighting climate change and said it would be a "crime" to spoil the environment for future generations.
Former Mexican President Vicente Fox also harshly criticized Trump for the withdrawl.
Fox has clashed with Trump since last year's presidential campaign, and he let loose Thursday with a series of tweets saying the decision "condemns this generation and those to come."
Fox tweets of Trump: "He's declaring war on the planet itself."
He accused Trump of "leaving a dark legacy just to satisfy your greediness" and surrendering the nation's future.
Fox concludes: "United States has stopped being the leader of the free world. @realDonaldTrump, single handed, took care of that."
Chinese Premier Li Keqiang says fighting climate change is a "global consensus" and an "international responsibility."
Speaking in Berlin about the Paris climate change accord, he said that "China in recent years has stayed true to its commitment."
Without mentioning the U.S. specifically, he said China has been "actively promoting the Paris agreement and we were one of the first countries to ratify the Paris agreement."
He added: "Fighting climate change is a global consensus, it's not invented by China... and we realize that this is a global consensus agreement and that as a big developing nation we should shoulder our international responsibility."
The European Union's top climate change official says Trump's decision to pull out of the Paris accord makes it "a sad day for the global community."
The EU's climate action commissioner, Miguel Arias Canete, said in a statement Thursday that the bloc "deeply regrets the unilateral decision by the Trump administration."
Canete says the 2015 accord is "ambitious yet not prescriptive."
He says the agreement will endure, and he pledged that "the world can continue to count on Europe for global leadership."
Canete also predicted that the EU would seek new alliances from the world's largest economies to the most vulnerable island states, as well as U.S. businesses and individuals supportive of the accord.
He added: "We are on the right side of history."