Oil retreated as hotter US inflation caused a spike in the dollar and the market continued to brace for more trade moves from US President Donald Trump.

West Texas Intermediate slipped about 1.5% to around $72 per barrel after adding almost 4% over the previous three sessions. US consumer price data on Wednesday came in higher than projected, causing a surge in the dollar that makes commodities priced in the currency less appealing.

Oil prices have slumped in the past three weeks as Trump’s tariffs threaten to spark trade wars that may weigh on crude demand, and OPEC warned in its outlook on Wednesday that US trade policies risk stoking further market volatility. The International Energy Agency’s monthly report is due on Thursday.

Nationwide US crude inventories rose 4.07 million barrels last week, the third straight gain, according to figures released Wednesday. Futures slightly pared losses as the increase was smaller than the 9 million-barrel buildup projected by the American Petroleum Institute.

Underscoring the environment of ample supplies, WTI’s prompt spread — the difference between its two nearest contracts — narrowed to 17 cents a barrel, the weakest since November.

The inventory buildup puts timespreads “within striking distance of switching to contango” in a matter of months, according to Robert Yawger, director of the energy futures division at Mizuho Securities USA.

There are tentative signs that US sanctions are hampering Russian crude flows. Several million barrels from platforms in the Pacific are stranded after the shuttle tankers that hauled them to China were blacklisted. Still, the US Energy Information Administration said Tuesday that it doesn’t currently expect a large hit to Russian output.