While the White House is not expected to explicitly say the United States is withdrawing from the 2015 Paris Agreement on climate change, and people familiar with the White House deliberations say Mr. Trump has not decided whether to do so, the policy reversals would make it virtually impossible to meet the emissions reduction goals set by the Obama administration under the international agreement.

In an announcement that could come as soon as Thursday or as late as next month, according to people familiar with the White House’s planning, Mr. Trump will order Mr. Pruitt to withdraw and rewrite a set of Obama-era regulations known as the Clean Power Plan, according to a draft document obtained by The New York Times. The Obama rule was devised to shut down hundreds of heavily polluting coal-fired power plants and freeze construction of new coal plants, while replacing them with vast wind and solar farms.

The draft also lays out options for legally blocking or weakening about a half-dozen additional Obama-era executive orders and policies on climate change.