Kenneth Kaunda, Zambia's founding president who led his country for 27 years and championed Africa's struggles against apartheid and HIV/AIDS, has died at the age of 97.

"KK" as he was popularly known, was being treated for pneumonia at the Maina Soko Medical Centre, a military hospital in Lusaka.

"I am sad to inform (members) we have lost Mzee (the old man). Let’s pray for him," his son, Kambarage, said on the late president's Facebook page.

The liberation hero ruled from 1964 after the southern African nation won its independence from Britain.

He shared a loss experienced by countless families in Africa when his son Masuzyo died of AIDS in 1986, and he began a personal crusade against the disease.

"This is the biggest challenge for Africa. We must fight AIDS and we must do so now," he told Reuters in 2002.

"We fought colonialism. We must now use the same zeal to fight AIDS, which threatens to wipe out Africa."

In 1991, he was forced to hold the first multi-party elections for 23 years, which he lost to long-time foe, trade unionist Frederick Chiluba.

Though he was widely admired as a warm and emotional man, the voters judged he had overstayed his welcome in office. (Reuters)