New US defence chief in Afghanistan
New US Defence Secretary Ash Carter has arrived in Afghanistan days after taking up the post, saying he wants "lasting success" for the country, the BBC reported.
Mr Carter will meet US commanders and Afghan heads on the unannounced visit.
He said he had made Afghanistan his first visit as the 10,000 US troops still in the country "come first in my mind, always."
Foreign troops ended their combat role in December but the nation still faces a bloody Taliban insurgency.
The US troops still in the country are engaged in training and advisory roles.
Mr Carter, who was sworn in on Tuesday, said: "We're looking for success in Afghanistan that is lasting.
"How to do that, what the best way to do that is, is precisely what I'm here to assess."