Crude oil prices continued to rise on Wednesday, closing at their highest level in nearly four weeks as investors worried about escalating tensions in the Middle East following the United Arab Emirates’ decision to suspend all financial and economic transactions with Iran, while vessel traffic through the Strait of Hormuz remains limited.

Brent futures settled at $91.62 per barrel, up 60 cents, or 0.7%. US West Texas Intermediate (WTI) crude rose 89 cents, or 1.1%, to $85.83 per barrel.

Both benchmarks closed at their highest levels since July 24.

“Crude futures continue to be supported by geopolitical tensions in the Middle East, now compounded by the UAE announcing that it has cut all financial ties with Iran because of the latest missile attacks,” said Dennis Kissler, senior vice president of trading at BOK Financial.

Strait of Hormuz in focus

On Tuesday, US President Donald Trump said that no talks with Iran were taking place and that the Strait of Hormuz was open. Tehran, however, maintained that the critical maritime passage remains closed.

The temporary ceasefire agreement expired on Monday, while a senior Iranian official told Reuters that the country was moving toward escalation because of the diplomatic deadlock. There were no reports of new strikes by either side on Tuesday.

Meanwhile, according to the Financial Times, Iran is considering military targets in Europe if Trump further escalates the war.

The oil market’s attention remains focused on the Strait of Hormuz, through which, before the US-Israeli war with Iran began in late February, approximately one-fifth of the world’s oil and liquefied natural gas (LNG) supplies passed.

Only six cargo vessels crossed the Strait on Tuesday, according to Kpler data. That was down from nine vessels the previous day and significantly below the daily average of 11 vessels during the preceding 10 days.

$100 oil scenarios return

Brent’s rise above $91 per barrel indicates that traders are now pricing in a higher geopolitical risk premium, according to Ahmad Assiri, a strategy analyst at Pepperstone.

He said the development creates conditions in which oil prices could return to triple-digit levels, bringing the possibility of $100 Brent back into focus.

Developments in Russia are also providing additional support for prices. Oil exports from western Russian ports fell to approximately 2.3 million barrels per day during the first half of August, 15% below the originally scheduled loading volume, due to problems at the port of Novorossiysk on the Black Sea.

US inventories increased

On the other hand, US crude inventories rose by 4.4 million barrels, to 428.8 million barrels, last week, according to the US Energy Information Administration (EIA), easing concerns about tight supply.

Globally, however, refineries continue to purchase large volumes of crude, taking advantage of high refining margins, while Ukrainian attacks on Russia’s refining sector are keeping global fuel supplies constrained, according to Kissler.

In the US, refinery utilization increased by one percentage point to 97.2%, according to EIA data.