At a meeting of climate diplomats, Turkey promised a world-class COP31 venue in Antalya, a seaside city that has previously hosted G20 and NATO conferences.

"We are ready to make COP31 accessible, functional and inspiring," Aysin Turpanci, an official from Turkey's directorate of climate change, told delegates at mid-year UN negotiations in the German city of Bonn.

She said Turkey's strategic position between Europe and Asia and its ability to bridge divides between developed and developing nations made it the ideal host.

As anxiety grows over the cost and availability of accommodation for this year's summit in the Brazilian city of Belem, she said Antalya boasted more than 600,000 hotel beds.

"The prices are able to serve participants from all levels," she told diplomats and non-governmental representatives at a special side event in Bonn to push Turkey's case.

Nearly 200 nations attend the annual COP summits, which rotate through five groups of countries that must nominate, by consensus, a candidate to host the marathon climate negotiations.

The "Western European and Other States" bloc is hosting in 2026 and two bids have emerged -- Turkey and Australia, which has proposed co-hosting with neighbouring Pacific Island nations.

- Persistent -

An Australian official in Bonn told AFP that Canberra was "working very hard to resolve the COP31 bid".

Earlier this month, the country's environment minister, Murray Watt, also used a platform on the world stage to push Australia's case.

"It's time for a climate COP in the Pacific region," Watt told government ministers at the UN Ocean Conference in Nice, France.

"COP31 would be an unprecedented opportunity to bring global attention to the unique challenges and opportunities in the Blue Pacific."

The Pacific is severely threatened by rising seas and worsening storms, and many small island leaders have urged Turkey to withdraw from the race.

But Ankara shows no sign of budging.

"We reiterate our candidacy for COP presidency," the country's deputy environment minister, Fatma Varank, told delegates in Bonn.

Veteran climate analyst Alden Meyer said Turkey was "definitely being very persistent in their bid".

"Everyone is wondering, what is the game here? What does Turkey really want?" Meyer, from think tank E3G, told AFP in Bonn.

"And it may or may not be anything related to climate", he added, pointing to possible trade or political goals.

What is clear -- a winning candidate is not now expected to be declared during Bonn as hoped, Meyer said.

"The decision may not be made until Belem, or just before," he said.