President Jacob Zuma was suffering from nothing more serious than fatigue, ANC secretary general Gwede Mantashe said on Thursday.

"The president is resting now and the reason that we have forced the president to rest is that we want him to be ready for the state-of-the-nation address. That is the issue," Mantashe said.

"My own view is that the president will be ready to deliver the... address. He is working on it by the way, working from home quietly, walking slowly and it gives him more time to think through the issues."

Mantashe qualified his comments by saying he was not a doctor, but said he believed everybody became exhausted sometimes and needed rest.

"You know sometimes you want to do certain things. Your mind tells you to do so but your body refuses to do it, and the cure is not to go to hospital and be treated by doctors, it is just rest."

He said all senior ANC officials would be asked to take time off in the near future to recover from the election campaign.

Zuma is due to open the new Parliament on Tuesday.

It will be his first public duty after he was briefly hospitalised in Pretoria last weekend.