Another round of unconfirmed reports about a potential U.S.-Iran diplomatic breakthrough sent fresh optimism rippling through oil markets on Monday, after Al Arabiya claimed that a Qatari-Pakistani mediation proposal had revived serious negotiations over Tehran's nuclear program.

Citing unnamed sources, Al Arabiya reported that Washington was prepared to allow Iran to continue enriching uranium to 3.67%, with Tehran supposedly agreeing to the proposed limit. The sources suggested that a preliminary agreement was increasingly likely, although neither side has publicly acknowledged such a breakthrough.

There were also claims that arrangements were underway to discuss the return of International Atomic Energy Agency (IAEA) inspectors to Iran, despite no clarity over the scope of their inspections or the conditions under which they would operate.

Crucially, neither Washington nor Tehran has confirmed the reported enrichment agreement, while a senior Qatari official has reportedly disputed details of the…