WASHINGTON — The Supreme Court’s surprise decision Tuesday to halt President Obama’s climate change regulation could weaken or even imperil the international global warming accord reached in Paris less than two months ago, climate diplomats said.

The Paris Agreement, the first accord to commit every country to combating climate change, had as a cornerstone Obama’s assurance that the United States would carry out strong, legally sound policies to significantly cut carbon emissions. Over history, the United States is the largest greenhouse gas polluter, although its annual emissions have been overtaken by China’s.

But in India and China, two of the top polluters, policy experts said the Supreme Court ruling threw the US commitment into question, and possibly New Delhi’s and Beijing’s.

“If the US Supreme Court actually declares the coal power plant rules stillborn, the chances of nurturing trust between countries would all but vanish,’’ said Navroz K. Dubash, a senior fellow at the Center for Policy Research in New Delhi. “This could be the proverbial string which causes Paris to unravel.’’

The court verdict does not block the climate change rule permanently but halts its enactment until legal challenges have been decided, which could take a year or more. Legal experts said the unprecedented decision to stop work on the rule before any court had decided against it appears to signal it could ultimately be overturned.

If that happens, “we’ll need to reassess whether the United States can meet its commitments,’’ said Zou Ji, of the National Center for Climate Strategy and International Cooperation in Beijing.

US inaction has long been the chief obstacle to climate change agreements. India and China in particular resisted action absent a climate change policy in the United States. Obama sought to change that with rules to cut greenhouse gas emissions from coal-fired power plants. On the basis of those rules, Obama won agreements from China and India to enact their own pollution reduction plans, and helped push other countries into signing on to the Paris measure.