Poor countries must demonstrate clearer accounting and transparency to back up their calls for trillions of dollars of climate finance, the president of global climate negotiations has said.

Mukhtar Babayev, the ecology minister of Azerbaijan, who will lead the Cop29 UN climate summit in November, urged governments in developing countries to draw up reports showing their progress on cutting greenhouse gas emissions, and their spending on the climate crisis.

“It’s very important to build this correct, good and honest trust between the parties,” he said in an interview in Baku, the capital of Azerbaijan. “It’s a very, very important step, the creation of a transparency mechanism between the countries.”

At Cop29 in Baku, countries will be expected to come up with a new global goal on supplying climate finance to poorer countries, to help them cut their greenhouse gas emissions and adapt to the impacts of extreme weather. Some governments from the global south are calling for the sums to reach more than $1tn a year.

These pledges are expected to be subject to bitter wrangling at Cop29, as rich countries are unlikely to agree to provide anything like such sums from their taxpayers but the role of other sources of finance – such as the private sector – is still in question.

Babayev said large sums would be required to help poor countries update their emissions-cutting plans, known as nationally determined contributions, or NDCs, in line with the need to limit temperature rises to 1.5C above pre-industrial levels.

He sees efforts to improve the transparency of accounting for emissions cuts and climate spending as a crucial first step. “It’s like a triangle. First, transparency. It’s trust between the parties. Next, finance. Next, NDC. Today we are looking to this triangle,” he said.

Transparency, or clear accounting, is one of the most vexed issues at the global climate negotiations, partly because of the difficulty of monitoring the many variables involved – from greenhouse gas emissions to the spending of climate finance – but chiefly because of deep sensitivities over national sovereignty, and unwillingness to submit to international monitoring.

Yet there are many examples of how a lack of transparency is hampering global efforts to tackle the climate crisis. Greenhouse gas emissions have frequently been found to be greatly in excess of those reported: for instance, the International Energy Agency found in 2022 that emissions of the potent greenhouse gas methane were 70% higher than countries had admitted.

Climate finance spending is cloaked in secrecy and subject to gross distortions: an investigation by Reuters last year found Italy had helped open a chain of ice-cream shops in Asia, and Japan had supplied money for a coal-fired power plant in Bangladesh and an airport expansion in Egypt, under the guise of climate finance.

Under the 2015 Paris agreement, countries must start to submit new transparency reports. Developed countries were required to submit theirs first, in 2022; for developing countries the deadline is the end of this year.

Babayev wants countries to submit their reports early if possible, well before Cop29 begins on 11 November, as a way to unblock the logjam on finance. If poor countries can show clearly they are making efforts to cut emissions, adapt to the impacts of the climate crisis and account for any climate finance they receive, developed countries will have less excuse for withholding climate finance from them.

“If all these sides deliver, if countries will submit the transparent picture of their activities, that will also be a very good argument for the developed world to deliver the priorities of the developing world,” Babayev said. “We would like to be the interconnector.”

Azerbaijan is heavily dependent on oil and gas, which make up more than 90% of the country’s exports and account for more than half of the state budget. Babayev said fossil fuel producers would have to play a key role in the Cop.

“We would like to invite all the countries, especially the fossil fuel producing countries, to be together in this process, to think how we can participate in this process,” he said. “Because we understand our responsibility.”

He said some fossil fuel producing countries were already helping poor countries with finance. “On a bilateral and multilateral basis, they’ve assisted developing countries to invest in their green transition,” he said.

Yalchin Rafiyev, the chief negotiator for Azerbaijan, said fossil fuel producers did not want to be labelled as the sole source of the problem, however. He pointed out that other sectors, such as transportation, were also large sources of carbon emissions.

“Fossil fuel countries – and I consider it a legitimate concern – don’t want to be labelled as polluter pays,” he said. “There is a growing acceptance that they have to be involved in some way, they are ready to provide their own contribution, but they don’t want to be labelled like they are doing a bad thing.”