Brent crude futures jumped sharply in early European trading after President Donald Trump declared that the ceasefire with Iran had ended.
The remark, reported by Bloomberg, sent energy prices higher as traders repriced the risk of renewed military action in the Persian Gulf.
Brent crude climbed to $77.30 a barrel, up $1.50 from midnight levels.
The move marks a sharp reversal from earlier in the week, when oil prices had fallen on reports that a formal US-Iran agreement was imminent.
The volatility underscores how quickly sentiment can shift in the energy complex when geopolitical narratives change.
The development follows a period of intense market speculation regarding US military strategy in the region.