"We are committed to the IPO of Saudi Aramco based on appropriate conditions and at the right time," Prince Mohammed told the pan-Arab daily Asharq al-Awsat in an interview published on Sunday.

He reiterated his earlier expectations that the IPO of Saudi Aramco "will take place in (late) 2020 or the start of 2021," almost two years later than expected.

Saudi Arabia plans to sell up to five percent of the world's largest energy firm and hopes to raise up to $100 billion.

Prince Mohammed said it was still premature to announce where the IPO will be held, adding that many requirements for the sale to go through had been successfully completed.

Riyadh has taken a number of key procedures in preparation for the IPO including issuing a law for hydrocarbons tax, appointing a new board for Aramco and allowing an independent auditing of the kingdom's oil reserves, the crown prince said.

Aramco has also opened its accounts books for the first time to international ratings agencies, declared the size of its profits and transformed into a public shareholding company, he said.

The IPO -- expected to be the world's largest stock sale -- forms the cornerstone of a reform programme envisaged by Prince Mohammed to wean the Saudi economy off its reliance on oil.