Ukraine's president has thanked Australia for its "brave" donation of 49 tanks, which he described as essential assistance in its defence against Russia's invasion.
The decommissioned M1A1 Abrams tanks are being given to Ukraine in a $245 million aid package after Kyiv called for them to be donated rather than scrapped or sold as Australia mulled what to do with the aged-out fleet.
"I thank (Prime Minister Anthony Albanese) and the people of Australia for today's announcement of essential defence assistance for Ukraine totalling $170.6 million," Ukrainian President Volodymyr Zelenskiy wrote on X.
"I am especially grateful for Australia's brave decision to provide 49 M1A1 Abrams tanks for our defence against Russian aggression."
The armoured tanks have cannons and machine guns and can hit targets at "extended ranges, day or night, even in adverse weather conditions", according to the Australian Defence Force.
Ukrainian ambassador to Australia Vasyl Myroshnychenko welcomed the announcement, saying it would help strengthen their military "given the scope of this war and how brutal it is".
"This will be of huge help and used for various defensive lines and defensive operations," he told AAP.
Ukrainian soldiers knew how to use the tanks, which had been donated by the United States in the past, he said.
Defence Industry Minister Pat Conroy will speak to his Ukrainian counterpart at a NATO defence ministers meeting in Brussels.
The Australian government had made it very clear that they would be supporting Ukraine for "as long as it takes" for them to end the war on their terms, he said.
"We're really privileged to be the largest non-NATO contributor of military assistance," he told ABC Radio National.
"The 49 very capable M1A1 Abrams tanks will help support the people of Ukraine in their valiant struggle to end the war on its on their terms, and it will help maintain pressure on Russia."
Ukraine will have the option to receive the tanks after some remediation works given they're near the end of their life, or to have their delivery expedited and used for spare parts or otherwise.
Australia will keep a small number of tanks to help transition to a newer fleet.
The move contrasts to the Australian government's earlier decision not to donate its fleet of decommissioned Taipan helicopters, which were sent into early retirement due to reliability issues and after a fatal crash during a training exercise.
Opposition home affairs spokesman James Paterson said the tanks donation was "unambiguously good news" but questioned why a similar donation was not made with the Taipans.
"The tragedy is that we didn't do this in other instances like this, for example, the retirement of the Taipan helicopters, which, instead of being provided to Ukraine, despite a request from Ukraine, instead were dismantled and buried in the ground, which is a total waste of a useful military capability that could have had a difference on the battlefield for Ukraine," he told Sky News.
It was a timely contribution from Australia given reports North Korean troops had been sent to help Russia and might be weighing a bigger deployment to parts parts of Ukraine annexed by Moscow, Ambassador Myroshnychenko said.
"That is really a serious escalation, especially the co-operation between Russia and North Korea, that is a huge concern to Australia in the Indo-Pacific," he said.
Russia has dismissed the reports as "fake news".
The tanks bring Canberra's total military aid contribution to Ukraine since Russia's invasion in February 2022 to $1.3 billion, which includes 120 Bushmaster vehicles.
A $250 million package announced in July by Defence Minister Richard Marles at a NATO summit included air defence missiles, guided weapons, anti-tank weapons, artillery, mortars and small arms ammunition.