Donald Trump will huddle with top climate and economic advisors Tuesday to discuss US participation in a global climate accord agreed at Paris, as the new president flirts with withdrawing.
After months of uncertainty, Trump appears to be edging toward a decision on whether to honor the 2015 deal to limit global warming.
A US withdrawal would seriously undermine global efforts to limit carbon emissions, which the vast majority of experts say are changing the climate in dangerous ways.
The United States is the world's number two carbon polluter, after China.
For US allies, Trump's wavering has uncomfortable echoes of president George W. Bush's decision to withdraw from the 1992 Kyoto Protocol.
That withdrawal scuttled a carefully worked global comprise and effectively delaying climate action by two decades.
The Paris accord was hailed as the last chance to stave off worst-case-scenario global warming, but was savaged by Trump during his presidential campaign.
Trump called climate change a "hoax" perpetrated by China, and promised to "cancel" the deal as president.
But after four months in office, Trump has yet to make his move.
According to a senior administration official, Trump and his aides will kick-off discussions in earnest on Tuesday.
"They are meeting tomorrow at 1:30pm," the official said, without giving further details.
Senior State Department environmental official David Balton said "the question of the US view of the Paris Agreement is still under consideration within the US government."
"Our president, has indicated that he plans to make a decision sometime over the next couple of weeks, but not this week."
It is unclear whether a US decision will come before the end of UN climate talks, which began on Monday in Bonn, Germany.
The 11-day haggle on the nuts and bolts of the deal is meant to start drafting a "rulebook" to guide member countries in the practical execution of the pact.
Officials from Barack Obama's administration argue that the deal is good for the United States.
"Withdrawal at this point would be a terrible abdication of American leadership and would damage the welfare of the American people," said former top climate advisor John Podesta.
Sue Biniaz, a former State Department legal adviser, is among those urging Trump not to make the binary choice of pulling out.
She indicated it is possible for the Trump administration to remain in the agreement but revise the emissions targets if necessary.
"It is clear from the agreement that if you do change your target, you are encouraged to change it in a more ambitious direction," she said.
"But it is equally clear that you are not legally prohibited from changing it in any direction that you choose."