Brazil, self-described champion of developing nations, invited the world’s dignitaries into the Amazon rainforest to showcase solutions to the global crisis of climate change.

Now, with just eight weeks before negotiations begin, Brazil faces a diplomatic migraine.

History’s biggest polluter, the United States, is likely to be a no-show. The billions of dollars that poor countries need to cope with climate catastrophes have not materialized. Activists accuse Brazil of hypocrisy by authorizing more oil drilling.

And pressure is mounting to overhaul the entire system of climate diplomacy, established by the Paris Agreement 10 years ago, because the countries that pollute the most aren’t cutting their emissions nearly fast enough to stave off irreversible damage to the planet.

Amid all this, Brazil hasn’t found a way to resolve a basic problem threatening the coming talks. Many diplomats are complaining of an acute scarcity of affordable rooms in Belém, the host city. Two-thirds of countries have yet to book a room.

“We can’t push the issues critical to our survival if we can’t even get there,” said Ilana Seid, a diplomat from the Pacific island nation of Palau, the very existence of which is threatened by climate change. “It is difficult to see how we will be able to fully represent ourselves.”

According to the leader of a group of African diplomats, Brazilian officials had suggested to some countries that their delegates may need to share rooms. Delegates objected to that idea.