Energy markets remain on tenterhooks as the prospect of prolonged war in the Middle East grows.

Oil prices have again risen above $100 per barrel as energy markets see little relief amid the biggest disruption to global energy supplies in a generation.

Brent crude, the international benchmark, surged more than 9 percent on Thursday as traders weighed the prospect of weeks, or even months, of turmoil in energy markets as the United States and Israel wage war on Iran.

Brent futures, which are traded outside of regular market hours, were priced at $101.13 as of 03:00 GMT.

Asian stock markets, including exchanges in Tokyo, Seoul and Hong Kong, opened sharply lower on Friday, following steep losses on Wall Street overnight.

The latest surge in oil prices came after Iran’s Supreme Leader Mojtaba Khamenei pledged to maintain the effective closure of the Strait of Hormuz, which normally transports about one-fifth of global oil supplies.

In a statement read out on his behalf on Iranian state television, Khamenei described Tehran’s threats against shipping in the waterway as a “lever” that “must continue to be used”.

US President Donald Trump struck a similarly defiant tone on Thursday, posting on Truth Social that stopping Iran from getting nuclear weapons was of “far greater interest and importance” than rising oil prices.

‘Lack of tangible goals in this war’

Traffic through the strait has effectively ground to a halt due to Iranian threats, with only a handful of vessels passing through each day, many of them claiming links to China, Iran’s key economic partner.

According to the United Kingdom Maritime Trade Operations (UKMTO) centre, no more than five ships have passed through the waterway each day since the US and Israel launched joint strikes on Iran on February 28, compared with an average of 138 daily transits before the war. At least 16 commercial vessels have been attacked in the region since the start of the conflict, according to the UKMTO.

Tehran has claimed responsibility for several of the attacks, including a strike on Wednesday that crippled a Thai-flagged vessel off the coast of Oman.

Efforts to bring calm to the market have so far done little to tame prices, which are up nearly 40 percent compared with before the start of the war.

The International Energy Agency’s (IEA) announcement on Wednesday that member countries would release 400 million barrels of oil from emergency stockpiles drew a tepid response among traders eyeing a daily shortfall in global supplies estimated at 15-20 million barrels.

The US Department of the Treasury’s issuance on Thursday of a temporary licence authorising countries to purchase sanctioned Russian oil that has been stranded at sea also failed to move the market, with Brent crude staying above $100 a barrel after the Treasury announcement.

“The key problem is a lack of tangible goals in this war,” said Adi Imsirovic, an energy security expert at the University of Oxford.

“It makes it hard for oil traders to see the light at the end of the tunnel,” he said.

Trump has repeatedly floated the possibility of using the US Navy to escort commercial shipping through the strait, but the Pentagon has yet to conduct such operations amid concerns about the risks posed by Iranian attacks in the narrow waterway.

In an interview with CNBC on Thursday, US Energy Secretary Chris Wright said that Washington was “not ready” to provide navy escorts but that such operations could begin by the end of the month.

“It’ll happen relatively soon but it can’t happen now,” Wright said.