The US Department of Energy (DoE) was due Wednesday to publish its latest market snapshot of energy stockpiles in the United States.
Last week’s data had shown that American reserves of motor fuel increased by 300,000 barrels to 213.4 million in the week to June 16.
That was sharply below the rise of 1.5 million expected by analysts but marked the eighth weekly increase in a row.
But the DoE had added that US gasoline demand was close to daily records. That was seized on by analysts as evidence that high energy costs had not eroded consumption.
Gasoline numbers are under the spotlight because the United States is currently in the peak-demand driving season — when many Americans take to the roads en masse for their summer vacations.
Elsewhere, "geopolitical risks continue to limit the downside in crude with Iran’s weekend reminder that it is prepared to use oil exports as a weapon in its nuclear dispute", Norrish of Barclays said.
Traders remained concerned over the unfolding Iranian nuclear energy crisis.
Iran had said Monday that it would only use its vast oil resources as a weapon of last resort in the international dispute over its nuclear programme.
On June 6, Iran was presented with an offer — backed by Britain, China, France, Germany, Russia and the United States — of multilateral talks and a variety of incentives.
The offer is conditional on the Islamic republic agreeing to suspend uranium enrichment work, the focus of suspicions that the Islamic regime wishes to acquire nuclear weapons.
Iran, which is the OPEC oil cartel’s number two exporter, denies it is seeking nuclear arms and insists its atomic programme is purely for electricity generation.