Delegates attending the COP30 summit in Belém, Brazil, encountered a symbolic reminder of an unresolved diplomatic contest when Australia’s and Turkey’s pavilions were placed side by side in the convention centre.

The two countries have for more than three years been locked in a standoff over who will host the 2026 climate-conference known as COP31.

Australia is championing a bid to host in Adelaide in partnership with Pacific island nations, emphasising that no COP has yet been held in the Pacific region and arguing that it would highlight the urgent climate risks facing small-island states.

Its bid is backed by the 15-nation Pacific Islands Forum and reportedly enjoys majority support among the 28-member Western Europe and Others Group (WEOG), the bloc responsible for choosing the host.

Turkey, however, remains in contention, insisting its bid to host in the Mediterranean resort city of Antalya still stands.

President Recep Tayyip Erdoğan has recently reaffirmed his position, triggering a fresh round of correspondence with Australian Prime Minister Anthony Albanese.

Mr Albanese told journalists in Sydney that Mr Erdoğan had written to him 24 hours earlier to confirm Turkey’s intent to host.

Under the United Nations Framework Convention on Climate Change rules, the host must be selected by consensus among WEOG members.

Although Australia is said to have backing from some 23 out of 28 members, the lack of formal withdrawal by Turkey means the decision remains in limbo.

The Executive Secretary of the UN climate body, Simon Stiell, has called the deadlock “unhelpful” and urged resolution so that preparations for COP31 can proceed.

Diplomatic efforts are intensifying.

Australia has proposed the summit be co-hosted with Pacific nations, while Turkey has floated “innovative solutions”, including sharing the conference presidency or hosting auxiliary meetings tied to COP31.

National and regional leaders are applying pressure: James Marape, prime minister of Papua New Guinea, urged Turkey to step aside, citing Pacific nations’ existential climate vulnerability and the importance of geographic equity.

Should Australia and Turkey fail to reach agreement by the conclusion of COP30, an as-yet uninvited fallback option would see Germany step in to host COP31 in 2026. German officials, however, have made clear they do not wish to assume that role.

The timing is pressing: detailed logistical planning, delegate arrangements and international financing depend on clarity, and despite more than a year of campaigning, the bid remains unresolved as the world’s most important annual climate summit prepares to transition to its next host country.