President Cyril Ramaphosa said on Wednesday the government will speed up economic reforms to revive an ailing economy and attract foreign investors, after his African National Congress party won re-election.

Analysts have said boosting South African growth and overhauling debt-laden power firm Eskom were post-election priorities for the ANC, after a decade of slow growth and rising joblessness.

"We have to embark on the reforms, speed up on them," Ramaphosa told investors in Johannesburg.

"(Last year) we embarked on an economic recovery stimulus package and we identified a number of reform issues that we needed to address, we are now going to do that with greater speed. We are going to ensure that the certainty that investors want to see is there," Ramaphosa said.

Ramaphosa said more details on how the reforms would be implemented would be announced in his State of the Nation address, scheduled for next month.

South Africa's economy grew an estimated 0.8 percent in 2018 after recovering from recession. Growth is forecast at 1.5 percent this year, and one factor in hitting that target will be how the government manages a restructuring of power utility Eskom. Power blackouts are a factor dragging on economic growth.

The government has pledged a 23 billion rand ($1.61 billion) a year bailout for Eskom over the next three years. The utility's debt stands at 420 billion rand.

"We have to address the issue of Eskom's debt. That is what we are doing with Treasury ... We are not going to allow (Eskom) to fail," Ramaphosa said.