The fate of jailed Australian Oscar Jenkins is set to be discussed in face-to-face talks between Prime Minister Anthony Albanese and Ukrainian President Volodymyr Zelenskiy in Rome.
Mr Jenkins faces 13 years in a Russian prison after a court found him guilty of taking part in an armed conflict as a mercenary, which denies him the protections provided to prisoners of war under the Geneva Convention.
The Australian government insists he was fighting as a member of the Ukrainian defence forces and should be entitled to humane treatment as a prisoner of war.
"This is an appalling decision from Russia, and another outrage in a long line of outrages when it comes to matters involving Ukraine," federal frontbencher Murray Watt told Sky News on Sunday morning.
"We consider this to be a sham trial, and we don't accept that Mr Jenkins should be treated this way."
Mr Watt said he was sure Mr Albanese would bring up Mr Jenkins' treatment and prospects for release with Mr Zelenskiy.
The pair are expected to meet on Sunday, Vatican time, on the sidelines of the inauguration of Pope Leo XIV in the Holy See.
On Saturday, Mr Albanese told journalists he was "outraged" by Mr Jenkins' incarceration and that Russia was continuing to abrogate its obligations to international law.
Mr Zelenskiy held direct talks with Russian officials for the first time on Friday as the two sides make abortive efforts to work towards a ceasefire deal.
Mr Jenkins was captured in occupied eastern Ukraine and taken into Russian custody last December.
He was seen in social media videos visibly bruised and shaken while being interrogated and beaten by a Russian-speaking captor.
The 33-year-old is believed to be the first Australian combatant reportedly captured by Russian forces.
All sides of politics have offered their support to Mr Jenkins, with opposition home affairs spokesman James Paterson calling his treatment "shocking".
Ukrainian Ambassador to Australia Vasyl Myroshnychenko has previously said his government added Mr Jenkins to its list of prisoners of war and would negotiate for his release in an exchange.
More than three years have passed since Russia launched its invasion of Ukraine on February 24, 2022.
