"We urge older persons to join us in teaching our young people what it means to be good citizens, who are guided by the understanding of respect and ubuntu," he said.

"You spend a lot of time with grandchildren, and can contribute to inculcating these positive values at an early age, so that we can build a better society."

Zuma was speaking at the celebration of international Day of Older Persons at the Presidential Guest House in Pretoria and said the day is an opportunity to celebrate senior citizens and to highlight their concerns.

The United Nations designated October 1, as International Day of Older Persons.

Zuma added that the police have been instructed to ensure that the needs of elderly people and other people with special needs are taken into account when they have a problem.

He said reports of women at the age of 94 years being sexually assaulted was not acceptable.

"Anyone who rapes senior citizens is not worth being called a human being."

The role of a grandmother was an important one as many grandmothers looked after children whose parents died, Zuma said.

He said that government extended the reach of the old age pension grant allowing men to obtain the grant at the age of 60 years.

"We trust that this has contributed a great to alleviating need and poverty amongst older men," he said.

"Older persons also qualify for free access to essential services such as water, health, housing, and energy. We trust that most of you know these services and access them."

Zuma also thanked the older generation for their contribution they make to society and their families.