President Trump, front, speaks at Environmental Protection Agency headquarters in Washington before signing an energy independence executive order in March. Behind him, from left, Vice President Pence, EPA Administrator Scott Pruitt and Interior Secretary Ryan Zinke. (Pablo Martinez Monsivais/AP)

Foes of the Paris climate agreement have gained the upper hand in the ongoing debate at the White House over whether the United States should pull out of the historic pact, although President Trump has yet to make a final decision, according to participants in the discussions and those briefed on the deliberations.

Senior administration officials have met twice since Thursday to discuss whether the United States should abandon the U.N. accord struck in December 2015, under which the Obama administration pledged to cut U.S. greenhouse gas emissions 26 percent to 28 percent below 2005 levels by 2025.

The president’s aides remain divided over the international and domestic legal implications of remaining party to the agreement, which has provided a critical political opening for those pushing for an exit. At this point officials are considering whether the United States should stay in the agreement but renegotiate it in some form, or opt out entirely. Even if Trump decides to abandon the agreement — which is not a treaty, and therefore did not undergo Senate ratification — it may take three years for the United States to formally withdraw from it.

On Thursday several Cabinet members — including Environmental Protection Agency Administrator Scott Pruitt, who’s called for exiting the accord; Energy Secretary Rick Perry, who wants it renegotiated; and Secretary of State Rex Tillerson, who advocates remaining a party to it — met with top White House advisers, including Trump’s daughter Ivanka Trump and her husband, Jared Kushner, and Chief of Staff Reince Priebus. Both Ivanka Trump and Kushner advocate remaining part of the U.N. Framework Convention on Climate Change, even though the president has repeatedly criticized the global warming deal.

During that meeting, according to several people who spoke on the condition of anonymity to discuss internal deliberations, White House counsel Don McGahn informed participants that the United States could not remain in the agreement and lower the level of carbon cuts it would make by 2025.

The Trump administration is working to unravel many Obama-era policies underpinning that pledge, and the economic consulting firm Rhodium Group has estimated that the elimination of those policies would mean the United States would cut its emissions by 14 percent by 2025 compared with 21 percent if they remained in place.

This interpretation represented a change from the White House counsel’s earlier analysis and is at odds with the State Department’s view of the agreement.

Susan Biniaz, who served as the State Department’s lead climate lawyer from 1989 until earlier this year, said in an interview Tuesday that the agreement reached by nearly 200 nations in Paris allows for countries to alter their commitments in either direction.

“The Paris agreement provides for contributions to be nationally determined and it encourages countries, if they decide to change their targets, to make them more ambitious,” Biniaz said. “But it doesn’t legally prohibit them from changing them in another direction.”

Ivanka Trump urged White House staff secretary Rob Porter to convene a second meeting Monday with lawyers from both the White House and the State Department. That session addressed the question of America’s obligations under the 2015 deal as well as whether remaining in the agreement would make it more difficult for the administration to legally defend the changes it was making to the federal government’s existing climate policies, but it did not reach a final decision. Pruitt, who is spearheading the effort to rewrite several Obama-era rules aimed at curbing greenhouse gas emissions, has argued that exiting the agreement will make it easier to fend off the numerous legal lawsuits he will face in the months ahead.

However an internal Sierra Club memo dated May 1, written by John Coequyt, who heads the group’s federal and international climate campaigns, concludes that even if environmentalists sue to challenge the administration’s lowering climate targets or withdrawal from the Paris accord, “it would be extremely difficult to prevail on the merits of either argument.”

Writing to Steve Herz, the senior attorney for the Sierra Club’s international climate program, Coequyt wrote that the group will still be able to sue over the administration’s push to rewrite current climate regulations, “the question will be whether the administration is properly exercising its domestic regulatory authority. The Paris agreement, and its enforceability in U.S. courts, will have no bearing on this issue.”

At a rally with supporters on Saturday, Trump said he would make a “big decision” on Paris within the next two weeks and vowed to end “a broken system of global plunder at American expense.”

Administration advisers on both sides of the political spectrum, however, emphasized that the president himself would decide what path to pursue when it came to the climate agreement.

“In the end, President Trump will make the final decision, regardless of where the staff conversations end up,” Thomas J. Pyle, who heads the conservative Institute for Energy Research and led the Trump transition team for the Energy Department, said in an email. “The environmental lobby is going to cause litigation problems on nearly every aspect of President Trump’s energy and environmental agenda whether or not the administration stays in the Paris agreement. Staying in Paris only gives them another target to shoot at.”

But Paul Bledsoe, who served as a White House climate adviser under Bill Clinton and is now a lecturer at American University’s Center for Environmental Policy, warned that the administration might face serious pushback from abroad if Trump seeks to withdraw from the agreement.

“The Trump team seems oblivious to the fact that climate protection is now viewed by leading allies and nations around the world as a key measure of moral and diplomatic standing,” Bledsoe said in an email. “The U.S. would be risking pariah status on the international stage by withdrawing from Paris, and even a fig leaf approach of technically staying in the agreement while ignoring most of its provisions would be better than pulling out altogether.”

Even as private deliberations continued this week, groups on both sides of the debate lobbied the president publicly. The governors of California, Colorado, Connecticut, Delaware, Hawaii, Minnesota, New York, Oregon, Pennsylvania, Rhode Island, Virginia and Washington state, all Democrats, sent a letter to Trump on Wednesday saying they “stand ready as state leaders to continue to support the achievement of the existing” U.S. international climate commitment “and if possible to go further, faster.”

Meanwhile the libertarian Competitive Enterprise Institute published a paper laying out the legal and economic case for exiting the agreement, stating, “Failure to withdraw from the agreement would entrench a constitutionally damaging precedent, set President Trump’s domestic and foreign policies in conflict, and ensure decades of diplomatic blowback.”