Donald Trump is expected to make good on one of his most controversial campaign promises this week: pulling the U.S. out of the historic 2015 Paris Accord on climate change, according to numerous reports published Wednesday.

Trump’s decision would deepen the growing rift between the U.S. and its closest international allies, as well as put the U.S. in rare company with Syria and Nicaragua as the world’s only nonparticipants in the landmark deal, though Nicaragua didn’t sign because it felt the goals were too limited. The country is on course to have 90 percent renewables by 2020.

The deal, ratified last year and signed by 194 countries, is designed to keep global temperatures to a 2C (3.6F) increase above pre-industrial benchmarks, a threshold scientists warn if passed will accelerate catastrophic changes to the world’s ecosystems.

By leaving Paris, the U.S. propels China and the European Union to the forefront of the global effort to combat climate change.

During the signing of the Paris Accord, it was then-U.S. President Barack Obama and Chinese President Xi Jinping who emerged as the most vocal leaders, often highlighting key aspects of the accord and making joint commitments to combat climate change.

“I suspect we won’t see an unravelling and domino effect of other countries following suit. I think it will probably just remain the U.S.”

With the U.S. out, China, along with the EU, becomes the de facto leader on global climate policy. Officials from China and the EU are preparing a Friday “joint declaration reaffirming their commitment to climate and energy policy and the implementation of the Paris agreement,” Reuters reported.

According to documents seen by the Financial Times, Beijing and Brussels will outline measures to accelerate what they describe as the “irreversible” shift away from fossil fuels and the “historic achievement” of the Paris Accord. The document goes on to say the two sides are “determined to forge ahead” with measures to “lead the energy transition” toward a global low-emissions economy.

News of the imminent withdrawal was met with derision by EU lawmakers in Brussels. “It is a decision that does not meet with the approval of the greatest majority of this house for which I speak,” said European Parliament President Antonio Tajani.

In Spain, Indian Prime Minister Narendra Modi and his Spanish counterpart, Mariano Rajoy, issued a joint statement that said taking action on climate change was a priority for both nations.

Earlier this week during a trip to Germany, Modi announced new cooperation between the two countries on climate change while confirming India would not pull out of the accord, even if the U.S. did.

On Tuesday in New York, U.N. Secretary General António Guterres warned that withdrawing from the climate change agreement would have negative economic and security implications for the U.S. Guterres added that “if you leave a void to others to occupy, you might be creating a problem to your own internal security.”

On Wednesday Chinese Prime Minister Li Keqiang landed in Berlin for talks with Chancellor Angela Merkel, in yet the latest signal of the strengthening ties between the two countries. Last week German Foreign Minister Sigmar Gabriel traveled to Beijing, where the two countries signed a joint commitment promoting free trade.

The growing friendship stands in stark contrast with U.S. relations with Berlin and the EU at large, which are in turmoil following Trump’s first meeting of G-7 leaders when Merkel noted, “we in Europe have to take our fate into our own hands.”

Some have expressed fear that a U.S. withdrawal could lead to a mass exodus of other participants, but Rob Bailey, research director of the energy, environment and resources department at Chatham House, said that was unlikely.

“Governments perceive there to be downside risks in terms of soft power and international standing in failing to live up to the commitment they have made,” Bailey said. “I suspect we won’t see an unraveling and domino effect of other countries following suit. I think it will probably just remain the U.S.”