Diplomats from around the world had planned to gather in Azerbaijan this week to focus squarely on raising the trillions of dollars needed to tackle global warming.

But so far, this year’s United Nations climate change summit has been dominated by another topic entirely: the U.S. election and the impending return of Donald J. Trump to the world stage.

When he comes back to the White House in January, Mr. Trump is widely expected to pull out of the Paris climate agreement and renege on America’s commitments to cutting greenhouse gas emissions.

That has world leaders and negotiators at the summit wondering how they can possibly strengthen efforts to curb global warming without the support of the planet’s wealthiest and most powerful nation.

For the moment, many countries are trying to put on a brave face.

“Success does not depend on one country alone — it depends on all of us,” said Yalchin Rafiyev, Azerbaijan’s deputy minister of foreign affairs and the lead negotiator at the climate summit, known as COP29.