Venezuelan President Nicolas Maduro has said his country will launch a cryptocurrency to combat a US-led financial "blockade", although he provided few clues about how the economically crippled OPEC member would pull off the feat.

"Venezuela will create a cryptocurrency … the 'petro', to advance issues of monetary sovereignty, make financial transactions and overcome the financial blockade," Mr Maduro said during his weekly televised broadcast.

The digital currency will be backed by Venezuelan reserves of gold, oil, gas and diamonds, he said during the near five-hour show, which included traditional Christmas songs and dancing.

"The 21st century has arrived!" Mr Maduro added to cheers, without providing specifics about the currency launch.

Opposition leaders scorned the announcement, which they said needed congressional approval, and some cast doubt on whether the digital currency would ever see the light of day in tumultuous Venezuela.

"It's Maduro being a clown. This has no credibility," opposition politician and economist Angel Alvarado said.

Still, the announcement highlights how US sanctions this year are hurting Venezuela's ability to move money through international banks.

Mr Maduro's move away from the US dollar comes after the recent spectacular rise of bitcoin, which has been fuelled by signs that the digital currency is slowly gaining traction in the mainstream investment world.

Nicolas Maduro says the new currency will be called the "petro". ( Reuters: Carolos Garcia Rawlins )

Cryptocurrencies typically are not backed by any government or central banks.

Bitcoin already has a strong following among tech-savvy Venezuelans looking to bypass dysfunctional economic controls to obtain dollars or make internet purchases.

Venezuela's traditional currency, meanwhile, is in freefall.

Currency controls and excessive money printing have led to a 57 per cent depreciation of the bolivar against the dollar in the last month alone on the widely used black market.

For the millions of Venezuelans plunged into poverty and struggling to eat three meals a day, Mr Maduro's announcement is unlikely to bring any immediate relief.

Economists and opposition leaders say the leftist Mr Maduro, a former bus driver and union leader, has recklessly refused to overhaul Venezuela's controls and stem the economic meltdown.

He could now be seeking to pay bondholders and foreign creditors in the currency amid a plan to restructure the country's major debt burden, opposition leaders said, but the plan is likely to flop.

Reuters