Brent crude climbed sharply in early European trading after US President Donald Trump declared that the ceasefire with Iran is over.
The remark, reported by Bloomberg, signals a rapid deterioration in the diplomatic standoff that had briefly calmed markets earlier in the week.
The energy complex reacted immediately to the news.
Brent crude rose to $77.30 a barrel, adding $1.50 since midnight.
The move underscores how quickly geopolitical risk premiums can re-enter energy markets when diplomatic channels appear to close.
This development marks a sharp reversal from Monday, when global financial markets surged following confirmation of a mutual understanding agreement between Washington and Tehran.