Afghan officials are optimistic that in the coming years the 12,000-strong force will be able to almost double, to 22,000 troops.
Despite having begun to train the Afghan Army in 2008, the U.S. only started to seriously put together the Afghan Air Force in the last three years.
A U.S.-backed militia in Syria faces its toughest fight as it tries to capture the former ISIS stronghold.
Twenty-three personnel have already been rescued.
It's the first large-scale operation against al-Qaeda in Yemen since 2015.
"Chris and Jon lived and died as warriors,” said Col. Toby Magsig, commander of the 82nd Airborne's 1st Brigade Combat Team.
It's the second attack in just as many days that has killed Western troops.
The Taliban claimed it targeted foreign forces in Kandahar.
"We have made an investment in you, and you have made an investment in the Coast Guard” the Coast Guard's top officer said.
