Shortly after trading began, a barrel of West Texas Intermediate (WTI) for May delivery rose around 8% to US$104.50, while June delivery of international benchmark Brent rose 7% to US$102.

Oil prices had sunk and stocks soared last week after Trump agreed to a two-week ceasefire mediated by Pakistan, despite its tenuousness becoming quickly apparent as Israel continued to strike Lebanon and the Strait of Hormuz remained effectively closed.

Talks in Islamabad on a long-term deal, led by US vice president JD Vance and Iran’s parliament speaker, failed to result in a deal, with both sides expressing pessimism.

Trump then announced he was ordering his own blockade of the Strait of Hormuz, which the US military later said would begin Monday and only apply to vessels travelling to or from Iranian ports.

Markets have been in turmoil since the launch of the war on Feb 28, with Iran effectively blocking the Strait of Hormuz, through which one-fifth of all global oil and gas normally flows.