He was speaking at a post-cabinet media briefing in Harare.
Earlier during the day, Reserve Bank of Zimbabwe (RBZ) governor John Mangudya ignited a media frenzy when he announced a new set of bank notes and coins shall be introduced within the next two weeks.
The central bank chief said the new currency will circulate alongside what has been commonly referred to as bond notes and coins.
He said the new exchange would consist of 5 dollar notes and 2 dollar coins and would be introduced gradually to prevent driving up inflation.
His announcement was construed as a government pledge to introduce a new currency that was independent of the current RTGS currency, altogether.
But Mangudya's government boss, Ncube, told the media that the new bank notes will not represent a new currency.
"This is not a new currency. We already have a currency which is the Zimbabwe dollar," Ncube said.
"All that is happening is a cash injection that is absolutely needed to ease the cash shortages and also to reduce transactions cost."
Ncube added, "We have noticed that if you buy goods in cash, the prices are substantially lower. It is only because there is a premium on cash.
"Legally, we have a currency and all it is a cash injection. There is no new currency, a Zimbabwe Dollar was put in place on the 24th of June…"
In June this year, government scrapped the multi-currency system that had been in use since 2009 when authorities dumped the once resented Bearer cheque notes whose denominations went into world record trillion dollars.
Following their difficult experiences with the country's volatile currencies, Zimbabweans now prefer foreign exchange such as US dollars and South African rands which are more stable.
