GettyImages-499326146
People hike on the Perito Moreno glacier in Los Glaciares National Park, part of the Southern Patagonian Ice Field, on Nov. 30, 2015 in Santa Cruz Province, Argentina. Mario Tama/Getty Images

U.S. President Barack Obama’s top climate negotiator Todd Stern on Thursday warned of “diplomatic consequences” if a new president tried to back out on commitments under the Paris climate accord signed in December. The comments were made just days after the U.S. Supreme Court temporarily froze Obama’s ambitious Clean Power Plan, which seeks to cut pollution from power plants.

Speaking to reporters in London Thursday, Stern said that the fallout would be similar to when former U.S. President George W. Bush pulled the U.S. out of the Kyoto Protocol in 2001.

“There was a lot of blowback that the U.S. got generally diplomatically across the range of diplomatic concerns and I have no doubt that it would be very significant if the U.S. were to do that with regard to Paris, probably much, much more significant than what happened before,” Stern reportedly said. “There is a record there that you can look at to have a pretty good sense that there would be diplomatic consequences.”

The Paris climate accord commits the U.S. to a 26 percent to 28 percent reduction in carbon emissions below 2005 levels by 2025. However, the agreement, along with Obama’s Clean Power Plan, has faced stiff opposition from many Republican presidential candidates — including front-runner Donald Trump — who have consistently raised doubts over studies and observations showing humanity’s impact on the climate.

“There is not a single candidate in the Republican primary that thinks we should do anything about climate change, that thinks it’s serious,” Obama said Tuesday. “Well that’s a problem. The rest of the world looks at that and says, ‘Well, how can that be?’”

The Clean Power Plan — issued last year — lays out rules that are the centerpiece of Obama’s aggressive efforts to tackle climate change. Under its provisions, the U.S. Environmental Protection Agency was given the power to force coal-fired power stations to cut carbon dioxide emissions by about a third by 2030, marking the first nationwide limit on carbon dioxide emission from power generation.

However, the plan, which required states to submit their emissions reduction plans later this year, faced immediate and fierce opposition from a coalition of Republican states, coal industry and mining groups, who argued that it was an overextension of the president’s executive authority.

Earlier this month, the Supreme Court decided to issue a stay at the behest of this coalition. A Federal District Court will now hear oral arguments on the climate rule in June, and is expected to issue its decision later this year. However, if an appeal is accepted by the Supreme Court, a final decision is unlikely before June 2017.

“We anticipate that the Clean Power Plan will be upheld,” Stern reportedly said Thursday. “But if for whatever reason it is not, then we will have to use other means to get to our target, but we are not backing off our target.”