Ukraine is working to resume the exchange of prisoners with Russia, hoping for the release of 1,200 Ukrainians, President Volodymyr Zelensky and his Security Council chief have said.
"We are ... counting on the resumption of exchanges," Mr Zelensky said in a video posted on the Telegram messaging app. "Many meetings, negotiations and calls are now devoted to this," he said.
His security chief, Rustem Umerov, said that he had held consultations in Turkey and the United Arab Emirates, with the support of Ukraine's partners, on resuming the process of exchanges.
"As a result of these negotiations, the parties agreed to return to the Istanbul agreements," he said.
"This concerns the release of 1,200 Ukrainians," Mr Umerov said in a statement on Telegram.
There was no immediate comment from Russia on Ukraine's statements.
The Istanbul agreements are prisoner-exchange understandings brokered with Turkish mediation in 2022, setting out rules for large, coordinated swaps between Russia and Ukraine.
Since then, the two have traded thousands of prisoners, though exchanges have been sporadic and often disrupted by frontline escalation in the war Russia launched against Ukraine in February 2022.
Mr Umerov said that consultations would take place in the near future to decide the procedural and organisational details of the process.
"We are working without pause so that Ukrainians who are to return from captivity can celebrate New Year and Christmas at home – at the family table and with their loved ones," Mr Umerov said.
Ukrainian troops struggle to fend off larger Russian army
The Russian army said it had captured two more villages in Ukraine's south, where it has advanced in recent days as Kyiv scrambles to hold on to Pokrovsk further east.
Exhausted and outnumbered Ukrainian troops are struggling to fend off a larger Russian army as Moscow's full-scale offensive nears its fourth winter.
The Russian defence ministry announced the capture of two villages, Mala Tokmachka and Rivnopillia, in the southern Zaporizhzhia region.
Mala Tokmachka is south-east of Zaporizhzhia city, and its capture endangers the nearby hub of Orikhiv.
Rivnopillia is in eastern Zaporizhzhia, where Russian forces now control territory to the north, east and south of the town of Gulyaipole.
Moscow's defence ministry published aerial footage of Rivnopollia, showing Russian soldiers waving Russian flags over several damaged village houses.
Russia occupies large swathes of the Zaporizhzhia region - one of four Ukrainian regions the Kremlin claims as its own.
Kyiv said Sunday it had hit an oil refinery in Russia's Samara region, a day after it said it struck another refinery in a region near Moscow.
"Units of the Ukrainian Armed Forces struck the Novokuibyshevk oil refinery," the Ukrainian General Staff said.
Ukraine has struck Russian infrastructure throughout the conflict.
In eastern Ukraine, fighting centres around control of the key logistical hub Pokrovsk, which hundreds of Russian soldiers have infiltrated in recent weeks, weakening Ukrainian defences.
Peace talks between Kyiv and Moscow are currently deadlocked, and a planned Budapest summit between US President Donald Trump and his Russian counterpart Vladimir Putin did not go ahead.
