Ceasefire negotiations between Washington and Tehran showed no sign of progress Thursday after the worst burst of violence in weeks, with the Tehran-backed Hezbollah militia rejecting a US-brokered truce proposal for Lebanon. The diplomatic impasse follows days of escalating cross-border fire that has raised the stakes for any negotiated settlement.

Hezbollah's refusal underscores the militia's autonomy in decision-making despite its reliance on Iranian support, complicating American efforts to contain the conflict through direct channels with Tehran. The rejected truce would have paused hostilities along the Israel-Lebanon border, where exchanges have intensified sharply since early October.

Oil markets have priced in a persistent risk premium since the violence erupted, with Brent crude holding above $75 as traders weigh supply disruption scenarios. Energy analysts note that the stalemate removes a near-term catalyst for price relief, keeping volatility elevated across Middle East-exposed assets.

The breakdown leaves the Biden administration with fewer diplomatic levers as regional allies press for containment. With Hezbollah dug in and Iran's proxies operating on independent timelines, the path to de-escalation has narrowed considerably.