Now, 23 years later, that boy, Theogene Ngamije, is a private in the Australian Army.

"No day was easy, it was hard. I was always scared, hungry and intimidated. I wished there was another planet on which I could make a living," Private Ngamije said in Canberra on Wednesday.

"On the good day, a day I can call being born again, a tall Australian soldier took a knee and offered me a piece of biscuit and Australian flag patch from his uniform.

"That kindness came when I needed it most."

He said the Australian peacekeeper saved his life and the lives of many other children who were displaced at the time.

"There are no words that can describe how thankful I was and remain even to this hour."

In January 2011, he arrived in Australia with his uncle and his family, a country he said "gave me hope and a home."

In his early days he thought of ways he could "pay back" the "beautiful nation, specifically the peacekeeping soldier that helped me."

He thought the best way to do so was to join the army. But Private Ngamije's journey didn't come instantly as he had to wait to become an Australian citizen.

In February this year, the long wait was over, Private Ngamije was able to enlist in the Australian Army.

"I chose to enlist into the army due to the help, inspiration and unforgettable rescue I received from that Australian soldier," he said.

"I pray that someday I get to change someone else's life."

Wednesday marks the 70th anniversary of Australian involvement in international peacekeeping efforts.

Australia first sent military observers on a United Nations Consular Commission to Indonesia in 1947, and since then has had tens of thousands of military and civilian operatives on station around the world.

In Indonesia, information from UN military observers ultimately helped the Indonesians win independence from the Dutch.

The anniversary was marked by a ceremony at the Australian War Memorial in Canberra lead by director Brendan Nelson.

Dr Nelson said the anniversary highlights another side of the Australian military experience, one of goodwill and development.

"Peacekeepers and the work they have done and continue to do in Australia's name are vital facets of the story we tell at the memorial," he said.

"It is a story of war but also a story of compassion, service and mateship. It includes interactions with our friends and neighbours during times of trouble and also of peace."

The identity of the Australian peacekeeper who gave Private Ngamije the biscuit is still unknown, but he said he hoped that he would meet him again.

"To the peacekeeping soldier that changed my life, from deep down in my heart I thank you," he said.

"I shall forever be grateful and keep carrying your load as a soldier."

Private Ngamije is currently posted to the Army School of Ordnance in Bandiana, Victoria.

A Royal Australian Air Force C-130J Hercules will make a flypast of Canberra on Thursday just after 10am, as part of the opening of the Australian Peacekeeping Memorial on Anzac Parade.