Ukraine vows to negotiate exchange for captured Aussie

Australian prisoner of war Oscar Jenkins' prospects of freedom have received a boost after Ukraine promised to lend their support in negotiations, but whether that will sway his Russian captors remains to be seen.

Ukrainian ambassador to Australia Vasyl Myroshnychenko said his government has added Mr Jenkins to its list of prisoners of war after Russian officials confirmed the 32-year-old from Melbourne was alive and in captivity.

His remarks followed a call between Ukrainian President Volodymyr Zelenskiy and Australian Prime Minister Anthony Albanese in which the pair discussed Mr Jenkins' welfare.

"He had a contract with the Ukrainian Defence Forces so all the international law applies to him. So he will get on that list," Mr Myroshnychenko told ABC TV on Wednesday.

"The Ukrainian government certainly will be negotiating his exchange."

There have been grave concerns for Mr Jenkins' safety since a video of him being interrogated by Russian soldiers in eastern Ukraine was circulated online in December.

Russia has previously expressed its view that foreign fighters serving with Ukrainian forces are mercenaries and can be liable to prosecution.

But because Mr Jenkins was a combatant fighting on behalf of Ukraine, he would qualify as a prisoner of war under the Geneva Convention, entitling him to legal protections, international law expert Carrie McDougall said.

She said Russia had previously shown little regard to its obligations under international law but Ukraine's promise to go into bat for Mr Jenkins could only be beneficial to his cause.

"The more countries that are using leverage to try and secure his release, that can only I think help his prospects," she told AAP.

"But the degree to which it might make a difference to Russian calculations is something on which it's very difficult to assess."

Mr Jenkins is believed to be the first Australian combatant in Ukraine captured by Russia during the conflict.

But Russia and Ukraine have previously conducted several prisoner swaps, including for foreign fighters helping Ukraine.

Britons Aiden Aslin, Shaun Pinner and eight other foreign nationals were released as part of a broader prisoner exchange in September 2022, in which nearly 300 prisoners were swapped between Russia and Ukraine.

In a phone call with Mr Albanese overnight ahead of the three-year anniversary of Russia's invasion, Mr Zelenskiy called for an investigation into how Mr Jenkins ended up in Russian hands.

"We must establish all the circumstances surrounding the case of Australian citizen Oscar Jenkins, who fought for Ukraine and has been taken prisoner by Russia," Mr Zelenskiy said on X.

He thanked Mr Albanese for Australia's "unwavering" support of Ukraine and said the two countries were working to expedite a new defence aid package.

"We discussed strengthening sanctions against Russia for its war, and Australia is ready to take further steps," the president said.

"We also addressed diplomatic efforts and appreciate Australia's firm stance that all substantive negotiations on Ukraine must include Ukraine - this is the only way to achieve a just peace."

Ukraine's efforts to help free Mr Jenkins were a reflection of the deep gratitude the country has for Australia's support, Dr McDougall said.

"You have allies and friends for when things go wrong, not for when things are all going right," she said.

It will be three years since Russia commenced its full-scale invasion of Ukraine on February 24.