Mattis visited the headquarters of Operation Resolute Support, the NATO-led mission to train and advise Afghan security forces and met top American commander General John Nicholson, Tolo news reported.
Addressing a joint press conference with Gen. Nicholson, Mattis denounced the Taliban and called them “barbaric enemy”.
“What they do makes it clear to me why we stand together to defeat them,” he said.
Mattis said he expects an ongoing dialogue with the Afghan leadership in order to provide his best assessment and advice to US President Donald Trump.
“We continue to stand shoulder to shoulder with the Afghans for the future of this country,” he said.
Referring to the Massive Ordnance Air Blast (MOAB) bomb the US forces dropped in Afghanistan’s Nangarhar province on April 13, he said it “was to send a very clear message to Islamic State. If they come to Afghanistan they will be destroyed.
“We are going to keep going until ISIS-K (Daesh Afghanistan) is defeated in 2017. There is no space for ISIS-K in Afghanistan.”
Mattis said the majority of the Afghan people rejected the Taliban and do not want to see them again in power.
The US Defence Secretary is expected to meet President Ashraf Ghani and other top leaders.