South African Finance Minister Enoch Godongwana said on Thursday he will not resign after the government's U-turn on a planned value-added tax (VAT) hike, despite opposition calls for him to quit.

"My job is to introduce money bills - nothing says they must be popular," he told Reuters on the sidelines of the International Monetary Fund and World Bank spring meetings in Washington.

Godongwana, who landed in the U.S. capital this week, already grappling with the worst rift in U.S.–South African relations in decades, was forced on Thursday to scrap a rise in the value-added tax that threatened the stability of the ruling coalition government.

The proposal to raise the VAT by 1 percentage point over two years, which was intended to boost state revenue, met resistance as Africa's most industrialised economy grapples with sluggish growth and public discontent over rising living costs.

The about-turn blows a 75 billion rand ($4 billion) hole in the medium-term budget and leaves Godongwana with the task of drawing up what he said was "a different fiscal framework in line with the new realities of revenue and spending."

"I still maintain that if the purpose for which the VAT was raised is taken into account, its reversal will have a negative impact on those issues - that cannot be disputed," he said.

The revamped fiscal framework will be keenly watched by S&P Global Ratings, which currently has a positive outlook on South Africa.

A credible outcome could secure the first credit rating upgrade for South Africa in two decades, while the opposite could raise future borrowing costs and dent investor appetite for the country.

"If you ask me, I don't think what will inform them is the noise," Godongwana said.

"What will trigger them is whether the final product is a sustainable budget."