An American official said the U.S. feels “very confident” Pakistani Taliban leader Hakimullah Mehsud was killed in a drone strike today. “They got Mehsud,” the official told ABC News.

Mehsud, who the U.S. government considers one of its most wanted terrorists, died when a missile struck his vehicle shortly after he left a mosque, a Pakistani intelligence source said. Another Pakistani intelligence source and senior Taliban members confirmed Mehsud’s death, though the Taliban has not officially acknowledged it.

White House National Security Council spokesperson Caitlin Hayden said her office was “not in a position” to confirm Mehsud’s death.

Mehsud’s death would represent one of the highest-level counter-terrorism victories for the U.S. since the death of al Qaeda leader Osama bin Laden.