Spokesman Jay Carney says the U.S. will work with the Afghan authorities as they investigate the killing of Ahmed Wali Karzai. The president's half-brother was shot to death while receiving guests at his home in Kandahar.
Carney says the Obama administration's prayers and sympathies are with the Karzai family.
The younger Karzai was the head of the Kandahar provincial council. Kandahar's governor identified the assassin as a person close to Karzai.