Deputy Crown Prince Mohammed bin Salman oversees the Public Investment Fund (PIF)

Saudi Arabia has unveiled its austerity plans as the nation prepares to cope with tumbling oil prices - but insists it will not start taxing people's incomes.

Deputy Crown Prince Mohammed bin Salman said his proposals would raise $100billion a year by 2020 as part of moves to balance the books.

The amount of non-oil related income would triple through subsidy cuts and new levies, he revealed.

It comes days after it emerged that the kingdom was preparing for the end of the oil age be creating a $2trillion investment fund which is set to be 'the largest on earth'.

In an interview with Bloomberg, the prince said there were no plans to tax incomes but that proposals were in the pipeline to impose a value-added tax and levies on luxury items, sugary drinks and energy.

It may also target expats by introducing a system similar to the US Green Card.

Bloomberg reports that non-oil income went up more than a third to $44billion last year.

He said: 'It’s a large package of programs that aims to restructure some revenue-generating sectors.'

Last week he said a Public Investment Fund (PIF) will eventually be large enough to buy Google, Apple and Microsoft with money to spare.

The prince, who oversees the fund, claims that the initial public offering could happen as soon as next year.

It came as the world’s biggest crude exporter insisted it will only freeze its oil output if other key producers, including Iran, take a similar measure.

‘What is left now is to diversify investments,’ the 30-year-old prince told Bloomberg, during an interview from the royal compound in the kingdom’s capital, Riyadh.

‘So within 20 years, we will be an economy or state that doesn’t depend mainly on oil.’

It is nearly 80 years since the first oil was discovered in Saudi Arabia but, with crude prices plummeting worldwide, the nation plans to shake its dependence on the market.

Oil prices are being hit in part owing to the return of Iranian crude to markets after crippling economic sanctions on Tehran were lifted following last year’s nuclear deal between Iran and world powers

One of the first steps will be for Saudi Arabia to sell shares in Aramco’s parent company, which will transform the oil giant into an 'industrial conglomerate'.

According to the prince, the son of King Salman, the sale of Aramco could come as early as 2017.

But if all goes to plan, the fund will eventually be large enough to buy all four of the world’s largest publicly traded companies – Apple Inc., Google parent company Alphabet Inc., Microsoft Corp. and Berkshire Hathaway Inc.

Although the proportion of foreign investments is currently at just five per cent of the fund, PIF plans to increase it to 50 per cent by 2020.

But Prince Mohammed said he doesn’t believe the kingdom has a ‘real problem’ when it comes to low oil prices, despite the fact the price of a barrel of crude oil has more than halved.

‘Undoubtedly, it will be the largest fund on Earth,’ added the prince. ‘This will happen as soon as Aramco goes public.’

The prince went on to confirm that Saudi Arabia will only freeze its oil output if other key producers, including Iran, take a similar measure.

‘If all countries agree to freeze production, we’re ready,’ he said.

It is nearly 80 years since the first oil was discovered in Saudi Arabia but, with crude prices plummeting worldwide, the nation plans to shake its dependence on the market

‘If there is anyone that decides to raise their production, then we will not reject any opportunity that knocks on our door.’

His remarks come ahead of a meeting of major oil producers led by Russia and Saudi Arabia set to take place in Doha on April 17, to discuss measures to stabilise prices, including a proposal not to pump out oil above a certain level.

Undoubtedly, it will be the largest fund on Earth. Deputy Crown Prince Mohammed bin Salman

Iran indicated it was ‘ready to participate’ in the meeting and demanded an exemption from the freeze in order to boost its exports, according to Russian Energy Minister Alexander Novak.

Oil prices are being hit in part owing to the return of Iranian crude to markets after crippling economic sanctions on Tehran were lifted following last year’s nuclear deal between Iran and world powers.

The upcoming meeting in Doha is a follow-up to talks in February between Qatar, Russia, Saudi Arabia and Venezuela, in which they first mooted the output freeze.