U.S. President Donald Trump announced a limited naval blockade targeting Iranian ports in the Strait of Hormuz after ceasefire talks with Iran in Pakistan failed.

The blockade will still allow ships traveling between non-Iranian ports, easing earlier fears of a full shutdown of the vital oil route.

Rising tensions pushed global oil prices sharply higher, reflecting concerns about energy supply disruptions.

Iran responded by warning it would confront military vessels while keeping the strait open for civilian traffic, the AP has reported.

Meanwhile, negotiations stalled over U.S. demands on Iran’s nuclear program, leaving uncertainty about what will happen when the ceasefire expires.