WASHINGTON (AP) — U.S. climate envoy John Kerry insisted Tuesday the United States was open to seeking middle ground on a controversy that threatens to overtake an upcoming world climate summit: a growing demand from poorer countries that the United States and other richer countries pay compensation as the culprits most responsible for wrecking the Earth's climate.

"We believe we have to step up, and we have a responsibility. We accept that," Kerry told reporters after an appearance at the Council on Foreign Relations, two weeks ahead of an annual U.N. climate conference, this time in Egypt's Sharm el Sheikh. With emissions from coal, oil and natural gas threatening to break through the threshold set in the Paris climate accord, the Biden administration and others are eager to keep summit negotiations on track for deeper emission cuts.

Flooding in Pakistan that has killed more than 1,000, displaced a half-million and caused an estimated $40 billion in damage has helped bring the compensation demands to the forefront ahead of the climate summit. Experts say economically struggling Pakistan historically has contributed just 0.4% of the fossil fuel pollution responsible for climate damage, compared to 21.5% for the U.S., 16.5% for China and 15% for the European Union.

As with Pacific island nations being swallowed by rising seas, sub-Saharan nations facing a future of droughts, and Arctic communities struggling with heat waves, Pakistan's leaders say they need financial help to deal with climate damage, rather than loans that put them further in debt. The U.S. and European Union for years have slow-walked proposals for formal summit negotiations on compensation, known as "loss and damage."

Kerry has been increasingly direct on the problems of that demand as the summit in Egypt nears, saying the idea of the U.S. or any other country coming up with a trillion dollars for it is a nonstarter, politically and otherwise.

Any move that threatens to put richer nations on the hook for legal liability is "going to be a problem for everybody, not just for us," Kerry said. "So how do you do this in a way that actually produces money, gets a system in place? We're totally in favor of that.

"We are working toward it, and we will in Sharm," he said. "We will not be, you know, obstructing."

Faten Aggad, senior climate diplomacy adviser for the African Climate Foundation, said in a briefing this month that past statements by Kerry and European leaders make "people doubt the EU and the U.S. commitment to move on loss and damage." She said her expectations are low for progress in Egypt on the issue.

Dealing with how rich nations pay for past pollution's harms will be the central issue of next month's negotiations, said David Waskow, international climate initiative director of the World Resources Institute, a think-tank.

"Loss and damage are happening now, hurting people and economies now, and must be addressed now," U.N. Secretary-General Antonio Guterres said last month as he amped up his rhetoric on the issue.

"This is a fundamental question of climate justice, international solidarity and trust," Guterres said.

In 2009 negotiations in Copenhagen, developed countries promised $100 billion a year in aid by 2020 for developing countries, both to help develop green energy and adapt to future warming. They haven't yet fulfilled the pledge but U.N. officials say it will happen soon.

Senior U.S. officials have suggested that negotiators at the Egypt summit could set up a framework for discussion on any special financing mechanisms for reparations and put off negotiations for an actual deal for two years.

Kerry emphasized a need to "reimagine" the role and function of multilateral development banks, organizations of donor nations and borrowing ones that provide development finance.

International financial institutions often wind up burying poorer economies in insurmountable debt, or forcing harsh economic reforms at a fast pace that creates social unrest.

China, where President Xi Jinping's continued reliance on coal-fired power plants and building of new ones is putting China on track to overtake the United States as the worst wrecker of the climate in history "of course" should contribute to any such fund, Kerry said.

Kerry also revealed what appeared to be a bare-bones level of communication continuing with climate counterparts in the Chinese government. That's despite Xi's breaking off of China-U.S. dialogue on climate and a range of other areas after House Speaker Nancy Pelosi angered China with her August visit to self-ruled Taiwan. China claims Taiwan as its territory.

"We've sent each other a few messages about trying to figure out how we might be able to resume" bilateral climate discussions, Kerry said.

"There's been communication about what would help the process," he said.