Crude oil and refined product futures prices were rising heading into Friday afternoon, as a possible agreement to reopen the Strait of Hormuz and restart Persian Gulf petroleum supply remains in doubt.

Crude prices were up about 1.3% at 11:30 a.m. ET, while RBOB futures were rising by 2.4% and ULSD contracts were seeing gains of about 1.3%. It's the second day of gains for petroleum futures.

The increases come amid news reports that an agreement between Iran and Oman to reopen the strait could include Iran seeking to block ships from the U.S. and Israel from passing through the waterway. That provision could undermine efforts to restart negotiations between the U.S. and Iran aimed at ending the conflict in the region.

Refined product prices are also being supported by continued Ukranian strikes on Russian refineries, further tightening global supply.

Despite Friday's gains, most petroleum futures contracts are set to end the week lower.