Global oil prices moved higher amid mounting doubts about whether the fragile ceasefire between the United States and Iran will endure, following a new wave of Israeli airstrikes on Lebanon.

The strikes prompted Tehran to caution that it would deliver a “regret‑inducing response” if the attacks persist. Meanwhile, US President Donald Trump stated that American forces would stay in the region until Iran adheres to what he described as the “real” ceasefire arrangement.

Oil markets had dropped sharply on Wednesday after news broke of an agreement to pause hostilities, which included reopening the strategically vital Strait of Hormuz.

However, renewed concerns emerged after reports indicated that Iran intends to keep the crucial maritime corridor closed in response to the Israeli operations, raising fears of prolonged disruption to global energy supplies.

Brent crude, the international benchmark, climbed 2% to $96.53 per barrel. In the United States, West Texas Intermediate gained 2.8% to $97.02, as tensions intensified around what Vice President JD Vance called a “fragile truce.”

Equity markets also surrendered part of the strong gains recorded the previous day. Japan’s Nikkei 225 finished 0.5% lower. In Europe, the UK’s FTSE 100 declined 0.4%, Germany’s Dax fell 1.3%, and France’s Cac slipped 0.8%.

“There’s clearly a degree of unease in global markets,” said Victoria Scholar, head of investment at Interactive Investor.

“We’re seeing markets give back some of their recent advances, and that reflects lingering uncertainty over whether the Strait of Hormuz is genuinely open.”

Sim Moh Siong, a strategist at Singapore-based OCBC, noted that attention in the coming days will center on energy shipments through the strait, particularly as questions remain about how Iran intends to regulate vessel movements.

A key element of the ceasefire deal stipulated that ships would be allowed to transit the Strait of Hormuz safely.

Yet vessels operating in the Gulf have reportedly received warnings from Iran’s navy stating that any ship attempting to pass through the strait without authorization “will be targeted and destroyed,” according to shipping brokerage firm SSY.

Only a limited number of ships have traversed the waterway since the agreement was announced — far below the roughly 130 vessels that crossed daily before the conflict began.

Even if traffic returns to normal levels, maritime tracking company Pole Star Global estimates it would take at least 10 days to clear the current backlog.

In recent weeks, several countries — including Malaysia, India, and the Philippines — have negotiated arrangements to ensure safe passage for their vessels.

“Planning has become extremely challenging because the situation changes day by day,” said Nils Haupt of container shipping company Hapag-Lloyd, which still has six ships in the Persian Gulf.

“Wednesday was a typical example. We heard that it would reopen and that movement was resuming, but by the evening that was no longer the case.”

Haupt added that the company is still awaiting official clarification on whether transit fees will be introduced for the Strait of Hormuz, cautioning that substantial charges could have serious consequences.

“If, for years to come, the fee for using the Strait of Hormuz runs into the millions — double or triple the cost of passing through the Panama or Suez canals — it would be extremely damaging for the entire industry.”

There is also uncertainty about whether Lebanon falls under the scope of the ceasefire agreement.

On Wednesday, Israel carried out its most intense bombardment of Lebanon during the current conflict, with at least 182 people reported killed.

Hezbollah announced on social media that it had launched rockets into northern Israel, describing the action as retaliation for alleged ceasefire breaches.

Vice President Vance is expected to participate in talks with Iranian officials in Pakistan on Saturday.