"This week's decline was the smallest that's occurred over the past 11 weeks, and a reversal to inventories building is expected to begin in the near term", said Jenna Delaney, senior oil analyst at S&P Global Platts Analytics. The S&P 500 index was last down 0.77 percent.
A voice for Wall Street in the White House, Cohn's resignation came after he lost a fight over Trump's plans for hefty steel and aluminium import tariffs.
"The generalized market anxiety over what could end up being a global trade war is dragging everything down", says Again Capital partner John Kilduff.
In its latest annual outlook published on Monday (5 March), the International Energy Agency said that better prospects for economic growth around the world would fuel strong demand for oil until at least 2023.
Crude inventories rose by 2.41 million barrels, lower than expectations.
That compares with a 2.5-million-barrel build in the previous week.
"However I don't believe that this strength will be long lived with rising US production and a strengthening dollar".
Crude stocks at the Cushing, Oklahoma, delivery hub fell by 605,000 barrels, EIA said.
The US government issues official inventory data today.
Asked whether or not surging USA production could hurt Canada's energy industry by eliminating the need for Canadian supply in its biggest market, IHS Markit's Calgary-based director, energy Kevin Birn said, "Not at this point".
US crude production hit a record high of nearly 10.4 million barrels per day (bpd) last week, according to the Energy Information Administration (EIA) Wednesday.
USA crude oil output is set to top 11 million barrels per day this year, making it the world's largest producer and threatening to offset the boost to prices from reduced supply from rivals within OPEC.
This would make it a bigger producer than Russian Federation, now ranked No. 1.
There will also be interest in the big CeraWeek annual industry gathering in Houston, which kicks off its third day with U.S. energy secretary Rick Perry, who likely will be asked to address impact of possible trade war on the United States oil sector; perhaps also the latest on potentially tightening USA sanctions on Venezuela.