Mike Pompeo Image Credit: AP

Secretary of State Michael Pompeo said eight governments are going to receive temporary waivers from US sanctions on the import of Iranian crude that snap back on Monday following President Donald Trump's decision to quit the Iran nuclear agreement reached in 2015.

Waivers are being granted to countries that have shown they've made "important moves"  toward reducing Iranian oil imports to zero, Pompeo told reporters on a conference call Friday. Of the eight countries receiving the waivers, six will import at "greatly reduced levels,"  he said. The other two are at or near zero but receiving a waiver gives them flexibility and time to end their dependence on Iranian oil imports.

Treasury Secretary Steven Mnuchin said the US is "intent on ensuring that global funds stop flowing to the coffers of the Iranian regime."

Ahead of Friday's call, a senior administration official said the eight countries included Japan, India and South Korea. China - the leading importer of Iranian oil - is still in discussions with the U.S. on terms, but is among the eight, according to two people familiar with the discussions who also asked not to be identified.

Mnuchin also signaled that Swift, the global financial messaging system, could be subject to sanctions if it doesn't comply with U.S. sanctions by handling transactions with Iranian institutions in violation of restrictions.

Global benchmark Brent crude has fallen about 15 per cent from over $85 a barrel last month on increasing speculation that at least some nations will get waivers, as well as signs that other OPEC members will pump more to offset any supply gap.