President Jacob Zuma on Wednesday said he would reign with an open heart if the African National Congress (ANC) wanted him to resign immediately.

"There is a few more months left before my task as president ends. In December, a new president will be elected. I don't know who it will be, the ANC will elect.

"In 2019, I will take off my hat of being the state president. I want to tell you that even if you said tomorrow I should step down from these positions, I would do so with a clean heart," Zuma told thousands of ANC members who had gathered to celebrate his 75th birthday in Kliptown, Soweto.

But, said Zuma: "I want to tell you my leaders that I will be a member of the ANC until I die."

Zuma said when he steps down he will dedicate most of his time to working for the ANC.

"I won't demand a salary because I will be a pensioner and I will work very hard."

ANC membership 'a blessing'

Zuma said his skill at debating ANC policies and issues would always have a place in the party.

"I don't want people to fool themselves that when I step down, I will disappear into obscurity. I will be at my branch. When there is a conference, I will be a delegate, I will be there with you."

He said when he joined the ANC he did not hold a position.

"To be a member of the ANC is a blessing, getting positions is an added blessing but do not allow who I am and for members of the opposition to judge me for you. You would have gone off the rails."

He said the members of the opposition will never be happy "but I will always be with you at the NGC or the policy conference".

Zuma said he has seen and learnt a lot in his 75 years.

"I have heard stories and I have experienced a lot. I have heard people say, I have heard that you can be friends with someone and then you can stop being friends with them.

"I have heard that do not trust a person, rather trust a rock. I have also decided to trust the rock I used as a young man, you cannot trust a person."

'We are used to being called names'

He said he joined the ANC before it was fashionable to do so.

"I have seen people come and go, I have seen heroes come and go, I have also seen heroes become cowards. I have seen people who said they would die for the nation changing. I have seen people who were taught politics fade into obscurity."

Zuma said in his lifetime he had had people tell him that they would stick by him only to turn around and stab him in the back.

"There are people today who do not know that we grew up being called names, they think when they call us names today we will hurt. No, we are used to being called names."

He said those that called him names suffered from a white people's disease: stress.

"I do not have stress. In the Zulu nation, stress does not exist, you can go to a traditional healer asking to be healed from stress, but they do not have muti for stress."

Opposition 'just doing their job'

He also took a jibe at members of the opposition who marched to the Union Buildings on Wednesday calling for his resignation.

"I do not want you to panic but there will be those who panic when the opposition talk the way they are talking. In reality they are just doing their job.

"They are meant to disagree with what others are doing, if they don't then they are not the opposition."

He said even if he sneezed or coughed, it would make headlines.

"They will say, he must step down, he does not respect people."

He said opposition parties criticised the ANC for not implementing its policies, but not the policies themselves.

"Do not be surprised when you see them in Parliament saying 'point of order'. They are trying to stop us from speaking to our people. Democracy allows for debates to takes place."

'They will attack the next president'

He said another new trend with critics was to take the ruling party to court.

If the opposition saw a presidential convoy, they would call for his resignation, Zuma said.

"Why would you pay attention to those people? But if they keep saying that, you too will get confused."

He said he felt sorry for those who marched against him during the National Day of Action.

"They are saying Zuma must go. Oh, how difficult it is to be in the opposition."

He said when the ANC elects a new president in December the criticism would not stop.

"They will attack the next president, you will forget that Zuma ever existed," he said.

He chuckled, saying the ANC should not panic because Nelson Mandela and Thabo Mbeki were also criticised.

'They can hate me, it is okay'

Zuma said he will not apologise for wanting land to be returned to black people.

"When I speak about land, inequality and unemployment, I am not doing it to excite people. They are the ones that broke the law first, they took what was ours, at least we are saying let us use the law and democracy to take the land, unlike some other party that wants to grab the land."

He said the ANC followed the Constitution.

"If we do not get the land then generations and generations to come will suffer. I cannot apologise for that, they can hate me, it is not new, they can hate me, it is okay, and say I am the devil personified, it is okay."

He said without radical economic transformation black people would suffer forever.

"Any black person who thinks I am wrong needs to be fixed."

Zuma to make dreams come true

He also paid tribute to the late Ontlametse Phalatse saying he was hurt by her death on Wednesday.

Zuma said Phalatse, 18, who suffered from the rare genetic disorder Progeria, had been meant to speak at his birthday celebrations.

"She wished to meet me, for a house to be built for her mother, a car to take her to the hospital and bills to be paid for a hospital oversees."

Zuma said he would make all her dreams to come true.

On Wednesday the family was gifted with a new car and Zuma has promised to help build them a new home.