Global oil prices rose on Tuesday after fresh military activity by the United States in southern Iran reignited concerns about a possible breakdown in already fragile ceasefire arrangements and ongoing diplomatic negotiations between Washington and Tehran.

The latest escalation comes at a time when both countries had been edging closer to a tentative understanding aimed at ending months of conflict and restoring stability to key energy shipping routes, including the strategically important Strait of Hormuz.

Brent crude, which had traded at about $97 per barrel on Monday, increased by roughly 3.5 percent the following day, pushing prices close to $100 per barrel as markets reacted to renewed geopolitical risk in the Middle East.

Reports indicate that US forces targeted missile-related infrastructure and other strategic sites in southern Iran. The action was described by American military officials as a protective response aimed at neutralising perceived threats against their personnel and assets.

The US military command overseeing the region maintained that the operations were intended to deter imminent risks, including activities linked to missile deployment and suspected attempts to position naval mines in sensitive waters.

Iran, however, rejected the justification and accused Washington of undermining the ceasefire arrangement. Tehran’s foreign ministry described the strikes in its southern region as a serious breach of the fragile truce, which had only recently begun to hold after weeks of hostilities.

Prior to the latest developments, both sides had signalled progress toward a preliminary framework that could pause the conflict and gradually reopen maritime trade routes through the Strait of Hormuz. The proposed arrangement reportedly included a transition period for negotiations on more complex issues such as Iran’s nuclear activities, alongside discussions on easing financial restrictions.

There were also indications that Iranian negotiators had sought the unfreezing of significant overseas assets as part of the broader diplomatic package being discussed in third-party mediation talks.

The conflict, which escalated earlier in the year following coordinated strikes involving US and Israeli forces on Iranian targets, has already disrupted global energy flows. It has driven up prices of fuel and related commodities, including agricultural inputs and food products, across multiple regions.

Shipping activity through the Strait of Hormuz, a corridor responsible for a substantial share of global oil and gas movement, has remained below normal levels since the escalation began, reflecting persistent security concerns.

While diplomatic engagement has not fully collapsed, the latest military actions have raised fresh doubts about the durability of any near-term peace arrangement and heightened fears of further disruption to global energy markets.