Best-selling children's author and Hiroshima bombing survivor Junko Morimoto urged the Australian Prime Minister to sign a treaty banning nuclear weapons before her death.
Morimoto was the author of My Hiroshima, her eye-witness account of the dropping of the atomic bomb on Hiroshima in 1945, when she was a teenager.
Morimoto was in her 80s when she died on Thursday morning.
Last month Ms Morimoto sent a letter to Malcolm Turnbull calling on his Government to sign and ratify the new Treaty on the Prohibition of Nuclear Weapons.
"When I was 13 years old, I survived hell on earth," the letter said.
"Our home collapsed around us but my brother, sister, father and I managed to crawl out of the rubble and survive the horrifying days and months that followed."
Australia is not a signatory to the treaty and the ABC has been told the Government considers the safeguards it contains to be ambiguous and weak.
It is also understood the treaty could undermine the separate nuclear non-proliferation agreement.
The United States and the United Kingdom have not signed the treaty, and none of the countries with nuclear weapons are signatories.
Morimoto's friend and translator Hiromi Kurosaka said Morimoto was very sick toward the end, and had assistance from the International Campaign to Abolish Nuclear Weapons to write the letter.
"She has experienced the fear of the war and the bomb and she's always been anti-nuclear weapons," Ms Kurosaka said.
Ms Kurosaka said a brain tumor had affected her friend, but she had been following the news out of North Korea and shook her head to show her concern.
"She was obviously upset about it. Basically saying she can't understand why this is happening."
In her book My Hiroshima Morimoto described her experience in detail.
"The banks of the river were crowded with people, everyone wanted to be near the water.
"I saw a girl with skin hanging from her nails.
"There was a child screaming, trying to wake her dead mother."