Addressing reporters in Johannesburg, she said no invitations were sent out and that it was up to people whether they wanted to attend the memorial.
"We don't issue invitations for funerals... we just confirmed with the Mandela family again that there were no invitations issued for this funeral.
"This is how we take care of funerals in our culture," Nkoana-Mashabane said.
Minister in the Presidency Collins Chabane said international heads of state and royalty had started arriving in South Africa.
"The fact that international leaders are making their way to South Africa at such short notice reflects the special place president Nelson Mandela holds in the hearts of people around the globe," he said.
"We are touched by the fact that many countries have declared periods of mourning, ordered that flags be flown at half-mast and draped or lit landmarks in the colours of the South African flag. We truly appreciate these gestures."
Chabane said South Africa appreciated the willingness shown by people mourning, reflecting, and celebrating Mandela's life and legacy.
He said 13 African heads of states had confirmed attendance.
International organisations, such as the United Nations, European Commission, and African Union, had also confirmed attendance.
Chabane said 11 eminent persons would also be in South Africa during this period.
US President Barack Obama would be accompanied by three of his country's former presidents: Jimmy Carter, George W Bush and Bill Clinton and their spouses, and 26 congressmen.
Brazilian president Dilma Rousseff would be accompanied by four former heads of state.
"We expect more confirmations, and we wish to reiterate that our international guests are most welcome as they join us at this difficult time," said Chabane.
News agency AFP reported on Sunday that the Dalai Lama, who has twice since 2009 been denied a visa for South Africa, was not planning to attend his fellow Nobel laureate Nelson Mandela's funeral, according to his spokesperson.- Send us your memories and photos of Nelson Mandela.
- Friends, colleagues, comrades and family of Nelson Mandela are invited to share their memories and tributes, and to light a candle for him, on his profile at Remembered.co.za.