Mattis visits Afghanistan as rockets hit Kabul
US Defence Secretary Jim Mattis is in Afghanistan - in his first visit since Donald Trump announced his commitment to the Afghan conflict.
The US recently confirmed it would send 3,000 extra troops to the country, to help local forces struggling against a resurgent Taliban.
Sixteen years after the US-led invasion, the Afghan government still only controls about 60% of the country.
Several rockets were fired near Kabul airport hours after Gen Mattis arrived.
Five civilians were wounded in the attack.
The rocket attack was claimed by both the Taliban, which said they had targeted Gen Mattis's plane, and their rival, the Islamic State group.
Gen Mattis held talks with Nato chief Jens Stoltenberg and Afghan President Ashraf Ghani about plans to strengthen Afghanistan's military.
Support from US-led Nato troops would give Afghan soldiers a "compelling battlefield advantage over anything the Taliban stands to mass against" it, Gen Mattis said.
The US would not allow "a merciless enemy to kill its way to power", he added.
US combat operations against the Taliban officially ended in 2014, but over 8,000 US special forces remain in the country backing Afghan troops.
At peak deployment levels in 2011, there were some 100,000 US personnel in the country.