The global benchmark crude was trading at a premium of US$8.38 to WTI for the same month.
USA crude, gasoline and distillate stocks rose last week, the Energy Information Administration said on Wednesday.
USA crude production continues to surge, however, as increased drilling in the prolific Permian shale basin helped push output to a record 12.4 million barrels per day (bpd) by the end of May.
President Donald Trump announced the US withdrawal from the nuclear deal with Iran in May 2018.
U.S. West Texas Intermediate (WTI) crude futures were at $52.94 per barrel on the New York Mercantile Exchange, down 31 cents, or 0.6%.
Oil prices have fallen sharply on concerns about slowing demand, but won some respite on Tuesday after a global stock market rally on hopes the Fed may trim interest rates.
The rise in USA stockpiles and fresh leg lower for crude prices comes as OPEC and its oil market allies are preparing to meet to decide production policy in the coming weeks.
U.S. President Donald Trump, in his latest public comments about the trade war, said he would likely decide on more China tariffs at the end of June, which followed his overnight threat to put tariffs on "at least" another $300 billion worth of Chinese goods.
Brent crude, the global oil benchmark, fell more than 3 per cent to below $60 in mid-afternoon trading in London after the release of the figures, before recovering some losses.
The familiar spectacle of analytical forecasts of crude inventory volumes proving to be wildly off the mark served on Wednesday to continue the commodity's price plunge, with the Energy Information Agency reporting that USA crude inventories rose 6.8 million barrels last week compared with expectations for an 849,000 barrel drawdown. Optimism over US trade relations with Mexico are also providing some support.
To shore up prices, OPEC has conveyed signals to extend the six-month-long supply cut deal with its allies into the second half of the year.
The group will set its policy when it meets later this month or in early July. "To me, that means drawing down inventories from their now elevated levels", al-Falih told Arab News. Investors are anxious that it could lead to a slowdown in the global economy, which could result in lower demand for crude oil across countries.
Oil prices hovered near five-month lows in the preceding session, however, sentiment continued lower as markets are under pressure amid surging USA supply and a stalling economy.
"Yesterday's upswing on the back of rising stock markets was halted by an unexpectedly sharp rise in United States crude oil and product stocks", Commerzbank said.
The combination of slower supply growth from US shale and continued restraint by Saudi Arabia and its allies should eliminate the prospective oversupply of oil later in 2019 and 2020.