TOKYO, March 22 — Oil prices rose early Monday after US President Donald Trump gave Iran a 48-hour ultimatum to reopen the Strait of Hormuz or face strikes on its energy infrastructure, while Israel warned its war effort could continue for several more weeks.

Shortly after the 2200 GMT (6am Malaysia time) market open, West Texas Intermediate for May delivery climbed 1.8 per cent to just above US$100 (RM394) a barrel before easing slightly.

North Sea Brent for May delivery rose at a similar pace to US$113.44 a barrel, before slipping to around US$111 about 45 minutes into trading.

On February 27, the day before the US-Israeli attacks on Iran began, WTI and Brent stood at US$67.02 and US$72.48 a barrel respectively.

Trump and Tehran have traded threats as the war entered its fourth week, with the US president demanding that Iran reopen the blocked Strait of Hormuz, through which about 20 per cent of the world’s oil and gas shipments usually pass.

The chokepoint has all but halted petroleum shipments through the narrow waterway, sending oil prices sharply higher.

Trump wrote on Truth Social late Saturday that US forces would “hit and obliterate” Iranian power plants — “starting with the biggest one first” — if Tehran did not fully reopen the strait within 48 hours, or by 23:44 GMT on Monday, based on the time of his post.

In response, Iran’s army said it would target energy and desalination infrastructure “belonging to the US and the regime in the region”, according to Fars news agency.

Meanwhile, Israel’s military chief Lieutenant General Eyal Zamir said Sunday that his forces were expanding their ground campaign against Iran-backed Hezbollah in Lebanon and warned the operation could be prolonged.

“We are now preparing to advance the targeted ground operations and strikes according to an organised plan,” he said.

In retaliation for the US and Israeli military campaign, Iran has carried out missile and drone strikes on infrastructure — particularly energy targets — in countries allied with Washington, as well as on ships in the Gulf, while specifically threatening vessels entering the strait. — AFP