The US Department of Energy's Strategic Petroleum Reserve data released Monday showed that SPR inventory levels as of Aug. 21 stood at 289.7 million barrels, down from 293.4 million barrels last week.
Of the total, sour crude stocks were at 191 mmbbls, down from 192.5 mmbbls in the prior week.
Sweet crude levels were down to 98.7 mmbbls from 100.9 mmbbls in the week ending Aug. 14.
SPR stockpiles are at their lowest level since 1982, according to Energy Information Administration data.
The decline reflects the Trump administration's ongoing move to release 172 mmbbls of oil, part of a coordinated worldwide effort by nations following the US-Israel joint campaign on Iran in late February.