After a brief spell of calm, global oil markets are once again facing chaos. Crude oil prices surged another 1% on Thursday after already recording a 5% jump in the previous trading session, as US President Donald Trump declared that the ceasefire agreement with Iran was “over.” At the same time, fresh US military strikes on Iranian targets heightened fears of disruptions to global crude supplies. Brent crude rose 1.31% to $79.04 a barrel, while US West Texas Intermediate (WTI) crude gained 1.28% to $74.46 on Thursday, extending the previous session’s rally of more than 5%. The gains came after US President Donald Trump threatened fresh strikes against Iran as early as Wednesday night. While declaring that the interim agreement to end the Iran war was “over”, Trump also ruled out a full-fledged war. Maritime authorities also raised the threat level for vessels transiting the strait to “severe” after two tankers were attacked on Tuesday.The rise in oil prices has renewed concerns over inflation, as any disruption to crude supplies from the Persian Gulf could increase energy costs. Higher inflation could, in turn, prompt the Federal Reserve and other central banks to raise interest rates, a move that can slow economic growth and weigh on investment markets.Speaking from the NATO summit in Ankara, Trump said he no longer considered the ceasefire with Iran to be in effect.“I think it’s over. I don’t want to deal with them any more; they’re scum,” Trump said on Wednesday.“They’re scum, they’re sick people, they’re led by sick people, and they’re vicious, violent people. And if they had a nuclear weapon, they’d use it.”Despite declaring the truce over, Trump said US negotiators could continue talks with Iranian officials.“Frankly, I don’t want to waste my time with them. Now, I’ll let our wonderful negotiators keep talking if they want, but I don’t see it,” Trump said.The interim agreement had paved the way for 60 days of discussions on unresolved issues, including Iran’s nuclear programme, the future administration of the Strait of Hormuz and access to billions of dollars in frozen Iranian funds. Trump’s remarks came after US and Iranian forces exchanged attacks in the Gulf.The US military’s Central Command later announced that it had launched fresh strikes on Iran aimed at keeping the Strait of Hormuz open to shipping. A US official told Reuters that the latest military action was expected to be larger than Tuesday’s attacks. Iranian media reported explosions in Bandar Abbas, Abu Musa, Bushehr and several other parts of the country.The renewed military action followed escalating tensions after Iranian attacks on ships in the Strait of Hormuz. The US subsequently revoked sanctions relief for Iranian oil sales that had been agreed under the interim deal reached between the two countries last month. Iran said on Wednesday that it had struck US military sites in Bahrain and Kuwait, triggering retaliatory US strikes.Before the conflict, around one-fifth of global oil supplies moved through the Strait of Hormuz. Concerns that continued fighting could disrupt shipments through the strategic waterway pushed crude prices higher in recent months, even going beyond the $125 per barrel mark.