President Barack Obama said on Monday that the violent death of Taliban leader Mullah Mohammed Akhtar Mansour by a US airstrike should send a "clear signal" to anti-American extremists that "we're going to protect our people." Obama also said Mansour's death was an "important milestone" in the years-long effort to bring peace to Afghanistan. "It has been confirmed that he is dead," Obama said on Monday during his first visit to Vietnam. "He is an individual who, as head of the Taliban, was specifically targeting U.S. personnel and troops inside of Afghanistan" who Obama sent there to help counter terrorism and help train Afghan troops. Mansour was killed when a U.S. drone fired on his vehicle in the southwestern Pakistan province of Baluchistan, though it was unclear whether the airstrike took place on Friday or Saturday. He had emerged as the successor to Taliban founder Mullah Mohammad Omar, whose 2013 death was only revealed last year. Obama authorized the attack and was briefed before and after it was carried out, aides said. Speaking at a news conference, Obama said the fatal attack on Mansour did not represent a change in US military strategy in Afghanistan, which is to help train Afghan forces. Obama ended the US combat mission in Afghanistan in 2014. "We are not re-entering the day-to-day combat operations that are currently being conducted by Afghan security forces," Obama said. "Our job is to help Afghanistan secure its own country, not to have our men and women in uniform engage in that fight for them." "On the other hand, where we have a high-profile leader who has been consistently part of plans and operations to potentially harm US personnel and who has been resistant to the kinds of peace talks and reconciliation that ultimately could bring an end to decades of war in Afghanistan, then it is my responsibility as commander in chief not to stand by, but to make sure that we send a clear signal to the Taliban and others that we're going to protect our people. "And that's exactly the message that has been sent," Obama said. Mansour was chosen to head the Afghan Taliban last summer after the revelation of Omar's death in 2013. The Taliban is the most powerful insurgent group in the war-ravaged country, where an estimated 11,000 civilians were killed or wounded and 5,500 government troops and police officers died last year alone. The Taliban seized power in 1996 and ruled Afghanistan according to a harsh interpretation of Islamic law until the group was toppled by a US-led invasion following the Sept. 11, 2001, attacks on New York and Washington. Almost 15 years later, about 13,000 troops are in the country from a US-NATO coalition, including around 9,800 Americans. While they are mostly focused on training and helping Afghan government forces battle the insurgency, about 3,000 troops are conducting counterterrorism operations against the Taliban and the extremist groups Al-Qaeda and the Daesh. — AP