The US official, who spoke on condition of anonymity, provided no further details, including when Hamza died or where.
President Donald Trump earlier declined to comment after NBC News first reported the US. assessment Asked if he had intelligence that bin Laden's son had been killed, Mr Trump told reporters: "I don't want to comment on it."
White House national security adviser John Bolton also refused to comment.
Separately, the White House declined comment on whether any announcement was imminent.
