Oil prices are heading for a weekly decline as improving flows through the Strait of Hormuz and the possibility of emergency fuel stock releases ease supply concerns, offsetting renewed uncertainty surrounding US-Iran talks.

Brent crude futures for December delivery, the international benchmark, were trading at $99.83 per barrel at 3:33 p.m. local time (1233 GMT) Friday, down 4.3% from last Friday’s close of $104.32, The Caspian Post reports, citing Anadolu Agency.

US benchmark West Texas Intermediate (WTI) crude futures for November delivery stood at $89.73 per barrel, marking a decline of about 2.9% from $92.41 a week earlier.

Oil prices began the week higher, rising above $100 per barrel after Iran ruled out negotiations with the US in the near term, reducing expectations for a diplomatic breakthrough.

Prices fell Wednesday following reports of increased flows through the Strait of Hormuz. Additional pressure came from US plans to release more crude from its Strategic Petroleum Reserve and expectations for tighter US monetary policy.

On Thursday, however, oil prices edged higher, pushing Brent back above $100 per barrel as stalled US-Iran talks raised concerns about a prolonged conflict and potential disruptions to supplies.

The latest diplomatic impasse followed Qatari-mediated talks in New York, after US Secretary of State Marco Rubio asked an Iranian delegation, which included Foreign Minister Abbas Araghchi, to leave. Iran’s UN mission denied that the delegation had been forced to depart.

The breakdown in diplomacy, along with reports that the US was considering a ban on diesel exports, countered easing supply concerns and provided support for oil prices.

On Friday, oil prices declined as expectations that European countries could release emergency diesel reserves reduced concerns over tight refined-product supplies. Renewed geopolitical tensions in the Middle East, however, limited the losses.