US President Barack Obama says Afghanistan's President Hamid Karzai remains "a critical partner" with the United States in the global war against terrorism despite Karzai's harsh recent criticism of the West. Obama tells ABC television in an interview from Prague that U.S. troops must be in Afghanistan because "3,000 Americans were killed" by an attack that was launched from there. The president says "those people are still out there, plotting to kill Americans." Obama said that if the United States succeeds only on the military side, but not on the civilian side, "then you're going to continue to have instability in the region."