Australian volunteer Sage O'Donnell died in the war unleashed by Russia against Ukraine, CNN reports.
The Australian Department of Foreign Affairs published a statement by the defender's mother.
"Sage was much loved by his friends and family. Sage’s humour, kind heart, values and laughter will be dearly missed. We are devastated by our recent loss of Sage," the statement said.
The Australian Foreign Ministry is providing consular assistance to the fallen soldier's family.
Earlier it was reported that Australia would send Bushmaster armoured personnel carriers to Ukraine.