US President Donald Trump is withdrawing the US from the Paris climate agreement, officials said today. The decision deals a staggering blow to the most ambitious global climate plan ever conceived.

“In order to fulfill my solemn duty to protect America and its citizens, the US will withdraw from the Paris climate accord," Trump said during a ceremony in the White House rose garden.

Trump said the US would also begin negotiations to reenter the climate agreement, or seek a new "transaction on terms that are fair for American citizens, its people, its taxpayers." 

Within hours of Trump's speech, Germany, Italy, and France said the agreement is "non-negotiable."

Take Action: Tell the US to Stand By Its Committments to Climate Change

Trump said that the US would stop immediately "all implementation of the non-binding Paris accords."

"The agreement doesn't eliminate coal jobs," Trump said. "It just transfers those jobs out of the US and ships them to foreign countries."

"I will work to ensure that the US is still the world's leader on environmental issues," Trump said. "I’m willing to immediately work with Democratic leaders to negotiate our way back into Paris on terms that are fair for the US and its workers, or to negotiate a new deal that protects our country and its taxpayers."

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Trump's decision was deeply unpopular with other US political and business leaders as well as world leaders.

Former President Barack Obama issued a statement while Trump was still speaking at the White House, encouraging cities and states to take action on climate change.

"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."

France's President Emmanuel Macron went on national TV to issue a statement to the US.

"Don't be mistaken on climate; there is no plan B because there is no planet B," he said. "I tell you firmly tonight: We will not renegotiate a less ambitious accord. There is no way."

Germany's Chancellor Angela Merkel said via a spokesman that she was "disappointed" in Trump's decision.

Hillary Clinton called the decision "a historic mistake. The world is moving forward together on climate change. Paris withdrawal leaves American workers & families behind."

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The announcement comes after Trump met with members of the G7, many of whom urged him to stay the course on the Paris agreement.

During a lunch with Macron last week, Trump said that he was under “heavy” pressure to withdraw and that "lot of people in my country are against this agreement," according to CNN.

In fact, 71% of the US public supports the agreement.

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Merkel also said she chided Trump at the G7.

"The entire discussion about climate was very difficult, if not to say very dissatisfying," she told reporters after a meeting. "There are no indications whether the United States will stay in the Paris agreement or not."

But the concerted effort wasn’t enough to convince Trump, who has been toying with abandoning the framework since he announced his candidacy for president.

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The decision supposedly hinged on one line within the treaty:  Article 4.11 states that any nation “may at any time adjust its existing nationally determined contribution with a view to enhancing its level of ambition.”

The Trump administration didn’t think that this would allow them to reduce the US’s commitments — which they plan to do — and didn’t want to incur penalties. Further, withdrawing from an agreement that they never intended to honor allows them to live up to a campaign pledge.

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Now begins an arduous process of withdrawal that could take years and will end the participation of the world’s largest economy and second largest emitter. 

Only two countries didn’t sign the agreement — the US is joirning war-torn Syria, and Nicaragua.

Many believe that this departure could cripple the agreement by discouraging other countries from escalating their commitments, an expectation that was baked into the plan. If the US won’t take steps to cut its emissions, then why should other, less-developed economies?

But other countries have stepped up in recent months to fill the leadership vacuum left by the US.

Both China and India are rising above their earlier commitments and seem poised to blow past their goals.

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And even as the US retreats on the federal level, states are picking up the slack.

California is sending diplomats all over the world in its quest to radically reduce its emissions; Virginia recently announced plans to stay committed to the Paris accords; and states across the US are investing heavily in renewables.