President Cyril Ramaphosa on Tuesday called for national unity and a new social compact to revive the economy and ease the plight of South Africa's poor majority.

"One thing that we will unite on is advancing the interests of our people," Ramaphosa said in his reply to the debate on his maiden State of the Nation Address.

He urged all parties represented in Parliament to work together to tackle a weak economy, poverty and joblessness.

"There will necessary be much contestation and vigorous debate...but I concur with the sentiment that we need to unite as parties to support this goal of a developmental state, as well as an inclusive economy," Ramaphosa  said.

He dismissed criticism from the opposition that he had used his address last week to announce a host of summits, including one on job creation, because he lacked a clear plan on how to steer the country in the wake of Jacob Zuma's forced resignation from the presidency last week.

Ramaphosa demurred that he had a blueprint in the form of the National Development Plan, and added that it was democratic tradition in South Africa to have a wide dialogue on every issue of critical importance.

The Constitution, he recalled, saw nearly two million submissions from the public when he was steering its drafting two decades ago.

"This is how our people want to be involved, they say nothing about us without us."

He responded to an emotional debate focused on his promise to push ahead with a new African National Congress (ANC) policy of land expropriation without compensation, by invoking Nelson Mandela and saying the measure would help to heal a historic injustice of black South Africans being stripped of their land.

Ramaphosa recalled that earlier in the day, on a walkabout in the working class suburb of Athlone, he had asked Cedric Alberts, a man in his seventies, where he lived. Alberts replied that he was evicted from District Six at the end of the sixties and to this day had never managed to acquire another home, but rented instead.

"This is a pain that needs to be addressed, it is a division we must heal," the new president said.

"So therefore what we need to do, is we need to interrogate the statement that expropriation with compensation is contrary to a flourishing economy."

He called the dispossession of the indigent through the Land Act early in the last century "the original sin", and said it had disempowered and impoverished black South Africans.

Expropriation without compensation should be part of a strategy to speed up land reform to revive the agriculture sector and boost food security and rural development, he said.

Responding to a rhetorical question from Congress of the People (Cope) leader Mosiuoa Lekota as to how government would distinguish between those it considered "our people", as opposed to the rest from whom land could be taken, Ramaphosa spoke of the poor.

He mentioned the homeless who live on street benches outside Parliament and others who had lost their jobs.

"These are our people," he said.