The system could generate $10 billion annually.

In a bid to create non-oil revenue streams amidst falling oil prices, the Kingdom of Saudi Arabia is also contemplating a 'permanent residency' system for the large expatriate population in the country.

In an exclusive interview to Bloomberg News, Deputy Crown Prince Mohammed bin Salman, who has been spearheading the country's economic diversification plan, he said that among revenue-raising plans, authorities were discussing a program similar to the US Green Card system, that would target the expatriates in the kingdom. He didn't divulge much about program.

Other steps that authorities were weighing in on are imposing a value-added tax and a levy on energy and sugary drinks as well as luxury items - in a bid to restructure subsidies.

'The Green Card-like program and a plan to allow employers to hire more foreign workers above their official quotas for a fee could generate $10 billion a year each, the deputy crown prince said.'

The Kingdom is home to nearly 10 million expatriates.

While the Green Card system could generate $10 billion - another $10 billion is expected to be generated from the fees imposed to exceed foreign worker quotas.

The measures would raise at least an extra $100 billion a year by 2020, which would more than triple non-oil income and balance the budget, Bloomberg reported.

Read the full interview here.