The latest escalation began after US forces struck two Iranian rocket launchers on Larak Island, an Iranian island located near the Strait of Hormuz.
The United States said the operation was aimed at preventing an imminent threat to shipping in the strategic waterway.
Iran responded by launching ballistic missiles toward US military facilities in Jordan, according to Iranian officials and regional reports. Jordan said its forces intercepted the missiles.
The renewed confrontation marks the first known direct US military action against Iran since late July, when fighting had eased as Washington and Tehran pursued efforts to reach a longer-term agreement.
The situation escalated further after US President Donald Trump claimed that Iran's Kharg Island was being 'blown to smithereens.'
Kharg Island is a major centre of Iran's oil industry and serves as the country's main crude oil export terminal.
Any major attack on its energy infrastructure could have significant consequences for Iran's economy and global oil markets.
However, there was no independent evidence that Kharg Island had been attacked when Trump made the claim.
Reuters also reported that the video Trump shared alongside his statement was AI-generated. An Iranian official dismissed the claim as false and described it as 'laughable.'
The White House and the US Department of Defense did not immediately provide details confirming an attack on Kharg Island.
The renewed fighting has already affected global energy markets. Oil prices rose on Monday as traders reacted to the possibility that the conflict could further disrupt shipping through the Strait of Hormuz, one of the world's most important routes for oil and gas transportation.
The Strait has remained a major point of tension throughout the conflict. Iran has threatened to restrict shipping through the waterway, while the United States has sought to keep the route open for international commercial vessels.
The latest escalation comes as Washington also increases economic pressure on Tehran.
US Treasury Secretary Scott Bessent said the United States plans to introduce new secondary sanctions against Iranian financial networks on a weekly basis, beginning with banks.
The developments have raised fears that the renewed military confrontation could undermine diplomatic efforts and trigger a wider regional crisis.
For now, the Strait of Hormuz remains at the centre of the dispute, with any prolonged disruption threatening global energy supplies and potentially pushing oil prices higher.
