The United States and Iran exchanged attacks for the first time in about a month, renewing security concerns around the Strait of Hormuz and sending oil prices higher.

US forces struck Iranian rocket launchers after detecting preparations to launch rockets carrying mines into the strait, according to Captain Tim Hawkins, a spokesperson for US Central Command. Hawkins said American forces were closely monitoring the area and remained ready to protect commercial traffic through the strategic waterway.

Iran’s Islamic Revolutionary Guard Corps subsequently launched missiles and drones against US air bases in Jordan early Monday in retaliation for the American airstrike, according to state-run IRNA. Jordan’s military intercepted eight missiles after they entered the kingdom’s airspace and destroyed them without damage, the Jordan News Agency reported.

The renewed military activity ended several weeks of relative calm and prompted a rise in energy markets. Brent crude gained 2.4% to trade above $90 a barrel.

The US strike was Washington’s first military action against Iran since late July. President Donald Trump’s administration has recently placed greater emphasis on economic pressure in an effort to secure concessions from Tehran. However, countries maintaining commercial ties with Iran have so far resisted US sanctions threats, while analysts have expressed limited confidence in the initial measures.

A sustained escalation could increase energy costs and add to inflationary pressures. The Strait of Hormuz previously handled about one-fifth of global oil and liquefied natural gas flows, making any threat to navigation a significant issue for energy markets and maritime trade.

The US military said last week that it had completed mine-clearing operations along internationally recognised shipping routes through the strait. US allies have nevertheless privately warned that mines may remain in the area.

Diplomatic and economic pressure is continuing alongside the military developments. Iranian Foreign Minister Abbas Araghchi said Iran remained willing to resume diplomacy with the US, but maintained that progress depended on Washington ending its pressure campaign. His comments followed discussions with Qatar, which has acted as a mediator in the conflict.

US Treasury Secretary Scott Bessent, meanwhile, pledged intensified economic action against Iran and its trading partners, including China, which purchases 90% of Iranian oil. He said Washington would discuss plans with allies to halt purchases of Iranian products, although no agreements had yet been reached.

Bessent also said the US planned to impose sanctions during the week on a second bank conducting business with Iran. The latest military exchanges and sanctions plans add further uncertainty for vessels, cargo flows and energy markets linked to the Strait of Hormuz.