A government official said Thursday that the waivers will be announced as soon as early next week.
The move follows a similar action in March, in which the US announced that 11 countries, including 10 European states and Japan, would be exempted from the financial sanctions due to their crude imports cut from Iran.
The US administration in late March approved sanctions on Iranian crude oil sector, which penalize other countries for buying or selling Iranian crude oil.
Under the law signed by US President Barack Obama late last year, the administration can exempt countries from sanctions if they significantly cut crude imports from Iran.
Washington has already urged 12 other countries, including India, China and South Korea, to follow the example of those exempted from the sanctions.
The US, Israel and some of their allies have accused Tehran of pursuing military objectives in its nuclear energy program.
Iran has repeatedly dismissed such allegations, arguing that as a committed signatory to the nuclear Non-Proliferation Treaty and a member of the International Atomic Energy Agency, it has the right to use nuclear technology for peaceful purposes.