Japanese shares plummeted in Thursday's early session after the U.S. launched fresh strikes on Iran, intensifying worries over energy disruptions from the Strait of Hormuz.
The Nikkei 225 fell 851 points or 1.2% to 67,900.43 at the opening bell.
U.S. President Donald Trump vowed to continue bombing until Tehran ceases attacks on ships and reopens the waterway, Fox News reported.
Elsewhere, IEA Chief Fatih Birol warned the global economy faces renewed strain if the conflict persists beyond weeks, while noting that Asian economies like South Korea and Japan are already feeling the impact.