By Kate Abnett, Alexander Cornwell and Elizabeth Piper

DUBAI (Reuters) -Azerbaijan is tipped to host next year’s U.N. climate summit, after striking a late deal with longtime adversary Armenia over its bid.

While some diplomats said other countries including Russia – which has blocked other host candidates – were expected to back Baku’s bid, there was no official confirmation from Moscow on Friday. The issue is still being negotiated at the COP28 climate summit in Dubai.

The decision over who will take over from current COP28 host, the United Arab Emirates, has been in an unprecedented geopolitical deadlock, after Russia said it would veto any European Union country’s bid to host. The EU has sanctioned Moscow over its invasion of Ukraine. Azerbaijan is not an EU member.

Azerbaijan confirmed late on Thursday it had struck a deal with Armenia that allows Baku to bid to host the COP29 talks without the threat of an Armenian veto.

The choice of a COP host needs support from all countries in the U.N.’s eastern Europe regional group.

“We received particular support from most of the countries [in the eastern European group]. Russia has also supported our bid,” Azerbaijan’s Ministry of Foreign Affairs spokesperson Aykhan Hajizada said on Friday.

A representative for Russia’s delegation at COP28 declined to comment. Russia’s Energy Ministry did not immediately respond to a request for comment.

Azerbaijan is an oil and gas producer and a member of OPEC+.

The United Arab Emirates has faced criticism for appointing Sultan al-Jaber, the head of its state-run oil company ADNOC, as president of this year’s COP28 summit.

Some delegates at COP28 have raised concerns about holding the world’s climate negotiations in an oil producer for a second year running.

“I do understand these concerns,” Hajizada said.

“Despite the fact that Azerbaijan is rich in oil and gas, Azerbaijan’s strategic goals are the diversification of energy, resources, especially applied to wind and solar energy,” he said.

Armenia agreed to back Azerbaijan’s COP hosting bid in exchange for membership of the eastern European group’s COP bureau.

The two Caucasian countries have been in conflict for decades, most notably over the region of Nagorno-Karabakh, internationally recognised as part of Azerbaijan but largely populated and controlled by ethnic Armenians. The region had been controlled by its ethnic Armenian majority until it was recaptured by Azerbaijan in September.

Bulgaria, an EU member, on Friday withdrew its own bid to host COP29, and in a statement welcomed the “constructive approach” from Armenia and Azerbaijan. Russia had previously blocked Bulgaria’s bid.

Diplomatic sources at COP28 told Reuters other eastern European countries are expected to back Baku’s bid to host – even though Moldova had also made a bid and Serbia was mulling one.

Diplomats are racing to find a deal before COP28’s scheduled end on Dec. 12.

The deadlock over the host has left next year’s COP29 summit host with little time to prepare for the massive gathering – which can bring its host nation diplomatic prestige, as well as heavy scrutiny over its own record in fighting climate change.

(Reporting by Kate Abnett, Elizabeth Piper, Alexander Cornwell in Dubai; additional reporting by Vladimir Soldatkin in Moscow; Editing by Andrew Heavens and Toby Chopra)