More U.S. troops are arriving in Afghanistan to help American diplomats and thousands of Afghans evacuate. The Pentagon said three-thousand troops were being deployed to the capital city of Kabul this weekend from nearby locations outside the country. The move comes as the U.S. speeds up evacuation flights in the face of a Taliban offensive that's isolating the Afghan capital. Afghanistan's second and third largest cities -- Herat and Kandahar -- have fallen to the Taliban in the past day.