Massacre makes Obama 'more determined' to exit Afghanistan By Caren Bohan and Ahmad Nadem WASHINGTON/KANDAHAR, Afghanistan (Reuters) - President Barack Obama said on Monday the massacre of 16 villagers by a U.S. soldier raises his determination to get American troops out of Afghanistan, while a U.S. official said the accused staff sergeant previously had suffered traumatic brain injury. Sunday's shootings triggered angry calls from Afghans for an immediate American exit. Obama said there should not be a "rush to the exits" for U.S. forces who have been fighting in Afghanistan since 2001 and that the drawdown must be carried out in a responsible way. The accused U.S. Army staff sergeant walked off his base in the southern province of Kandahar in the middle of night and gunned down at least 16 villagers, mostly women and children. Defense Secretary Leon Panetta said the death penalty could be sought in the U.S. military justice system against the soldier, whose name has not been publicly disclosed. Referring to Sunday's massacre, Obama said in an interview with KDKA, a CBS affiliate in Pittsburgh: "It makes me more determined to make sure we're getting our troops home." It's time. It's been a decade, and, frankly, now that we've gotten (Osama) bin Laden, now that we've weakened al Qaeda, we're in a stronger position to transition than we would have been two or three years ago," Obama added, referring to the al Qaeda leader killed by U.S. forces last year in Pakistan. Panetta portrayed the shooting as an isolated event that would not alter plans for a gradual, orderly withdrawal of American combat forces by the end of 2014. War is hell. These kinds of events and incidents are going to take place, they've taken place in any war. They're terrible events. And this is not the first of those events, and it probably won't be the last," the U.S. defense secretary told reporters on a flight to Kyrgyzstan. But we cannot allow these events to undermine our strategy or the mission that we're involved in. The Army staff sergeant accused in the incident was treated for traumatic brain injury suffered in a vehicle rollover in 2010 during a previous deployment in Iraq, a U.S. official said. The official, speaking on condition of anonymity, said it was premature to state whether there was any link between the brain injury and Sunday's shootings. Obama was pressed in another separate interview with WFTV, an ABC affiliate in Orlando, on whether there were parallels between the killing of 16 Afghan villagers and the notorious 1968 My Lai massacre of the Vietnam War. "It's not comparable," Obama said. "It appeared you had a lone gunman who acted on his own," he said of the Afghanistan incident. In no way is this representative of the enormous sacrifices that our men and women have made in Afghanistan. Panetta said the goal was to try the case within the American military justice system. Asked whether the death penalty could be considered in this case, Panetta replied: "My understanding is that in these instances that could be a consideration." Obama and America's NATO partners intend to pull most of their troops out of Afghanistan by the end of 2014, leaving an inexperienced local army in charge. Officials in Washington denied that the killings might alter that timetable. But securing a full deal may be far more difficult now. "We have benefited little from the foreign troops here but lost everything - our lives, dignity and our country to them," said Haji Najiq, a Kandahar shop owner. The cost of the war has already exceeded $500 billion and more than 1,900 U.S. troops have been killed, with the total number of foreign troops killed approaching 3,000. Additional reporting by Ahmad Haroon ̀in KANDAHAR, Hamid Shalizi and Mirwais Harooni in KABUL; Susan Cornwell, Missy Ryan, Alister Bull, Matt Spetalnick in WASHINGTON; Michelle Nicols, Louis Charbonneau and Emily Flitter in NEW YORK; Editing by Will Dunham