Oil prices rebounded on Tuesday after the United States carried out what it described as defensive strikes in southern Iran, raising fresh concerns over the fragile ceasefire and ongoing peace talks between Washington and Tehran.

The strikes came amid expectations that both countries were nearing an agreement to end the three-month war and reopen the Strait of Hormuz for the free movement of oil shipments.

From about $97 per barrel on Monday, global benchmark Brent crude futures rose by roughly 3.5 per cent on Tuesday to around $100 per barrel.

According to reports, US forces struck missile-launch sites and other targets in southern Iran on Monday, even as the Donald Trump administration signalled that a peace agreement between the two sides could be close.

In a statement, the US Central Command said the attacks were defensive in nature. “US forces conducted self-defense strikes in southern Iran today to protect our troops from threats posed by Iranian forces. Targets included missile launch sites and Iranian boats attempting to emplace mines,” CENTCOM spokesman Capt. Tim Hawkins said.

Reacting, Iran accused the United States of violating the ceasefire with the strikes. Iran’s Foreign Ministry said the attacks in the southern Hormozgan province, where Iranian media reported explosions early on Tuesday, amounted to a “gross violation” of the fragile ceasefire that has been in place for nearly seven weeks, according to Reuters.

Both sides had earlier indicated progress on a memorandum of understanding that could halt the war and restore shipping activities through the Strait of Hormuz, while giving negotiators 60 days to address more contentious issues, including Iran’s nuclear programme.

Reports also indicated that Iranian negotiators had pushed for the proposed agreement to include the release of billions of dollars in frozen assets during talks held in Qatar.

The war, which began with US and Israeli strikes on Iran on February 28, has triggered a major oil supply shock, increasing the costs of fuel, fertiliser, and food globally. Iran had responded to the attacks by launching drones and missiles at Gulf states hosting US military bases.

Traffic through the Strait of Hormuz, which accounts for about one-fifth of global oil and liquefied natural gas trade, has remained significantly below normal levels since the conflict began.

Although diplomatic efforts are continuing, there are growing fears that the latest US strikes could further escalate tensions in the Middle East and disrupt global energy supplies.