BONN, Germany — Climate negotiators were supposed to spend the next 10 days in Bonn doing technical work on rules to fulfill the Paris climate agreement ahead of November’s COP23 global climate summit.

Instead, they’re transfixed by the prospect that the administration of President Donald Trump will fulfill his campaign pledge and abandon the agreement; top officials are scheduled to meet in Washington Tuesday to determine their next steps.

“It’s clear that [the U.S.] won’t abide by the commitment,” a senior climate negotiator from Africa told POLITICO in Bonn. “They are de facto out of the Paris agreement, now it’s a matter of making it de jure.”

A U.S. decision to pull out, which could come this week, will “damage the process,” said an EU official. “It’s going to be problematic, even a benign disengagement. Because in climate negotiations you need to drive, you need to push, and the previous administration was definitely instrumental in pushing other economies forward.”

The U.S. is the world’s second-largest greenhouse gas emitter after China. With the shrunken American delegation in Bonn acting more as place-holders than as negotiators, the rest of the conference is scrambling to figure out what happens to climate change efforts without the U.S.

“At the moment we all equally recognize that they’re waiting for clear policy directions,” Amjad Abdulla, a delegate from the Maldives and chief climate negotiator for the Alliance of Small Island States, told POLITICO.

“The good thing is they’re letting us move on with the process.”

European diplomats have been working for months to convince the Trump administration to stay in the pact, arguing that climate change is no longer a niche concern but a central issue in international diplomacy.

The previous administration of Barack Obama played a key role in pushing through the final Paris agreement in tandem with China in 2015, and the two coordinated to ratify it in record time last year.

Now delegations are warning the U.S. about the consequences of departure.

“If you want to be part of the international community, anyone going solo is not going to benefit,” Abdulla said. “The whole beauty of this multilateral process is we’ve been able to unite the world.”

The world has been prepping for this moment ever since Trump’s unexpected victory in November — an event that shook delegates at the COP22 summit then taking place in Marrakech, Morocco.

Brussels has since ramped up its diplomatic efforts. Miguel Arias Cañete, the EU’s climate action and energy commissioner, visited Canada and China earlier this year to show that the world’s major economies are serious about implementing the deal regardless of the U.S. An EU-China leaders’ summit on June 2 is expected to signal deeper climate and diplomatic ties between the two.

Brussels is also in “permanent contact” with its African and Latin American allies, the EU official said, as well as with members of the High Ambition Coalition, a grouping of countries crucial to reaching the Paris agreement.

With the U.S. taking a back seat, other countries are stepping in — both to push for more aggressive policies and to bask in the international publicity of being seen as a climate good guy. China has unexpectedly become one of the bulwarks of the global rule-based system, while the EU senses there might be an opening to up its diplomatic game.

“The EU has always been a trustworthy partner because the EU has always delivered,” said Tosi Mpanu-Mpanu, the lead negotiator for the Democratic Republic of Congo.

Europe and its allies understand that the possible U.S. departure leaves a big hole in efforts to tackle climate change. The Paris agreement’s aim is to keep global warming to below 2 degrees Celsius, and eventually 1.5 degrees, by the end of the century. But scientists are warning that the window for meeting that target is closing fast, with the World Meteorological Organization saying average temperatures last year were 1.1 degrees Celsius above pre-industrial levels.

The Trump administration is already making that task more difficult by gutting some of the environmental policies championed by Obama and encouraging a return to coal and to more oil and gas drilling.

“The Canadians said, ‘Listen, we definitely need to push the agenda forward, we definitely want to be with the Europeans in driving the process,'” the EU official said. But “it is definitely very, very difficult to fill any vacuum of leadership from the Americans.”