He told a news conference in Brussels on Monday the Afghans forces -- trained, helped and assisted by NATO troops -- were responsible for the security of their country.
“We need tailor-made approaches to the different countries we are working with. We have one approach in Afghanistan and we must not forget that Afghanistan is about fighting terrorism."
“The reason why we went into Afghanistan was a direct response to a terrorist attack on the United States and the main reason why we still are there is to prevent Afghanistan from becoming a safe haven for terrorists.”
NATO saw a 60 percent spike in "cyber incidents" in 2016, compared to the previous year, he said while launching his annual report for 2016, when experts dealt with an average of 500 "cyber incidents" a month.
The alliance was doing more to project stability by training local forces in Afghanistan and Iraq to fight terrorism and sending training teams to Jordan, Morocco and Tunisia, Stoltenberg added.
With NATO AWACS planes supporting the Global Coalition to Counter-ISIL, a new intelligence division has been set up to deepen its understanding of the threats it faced.
In 2016, he said, 23 NATO allies increased their defence expenditure in real terms by 3.8 percent, which added up to 10 billion US dollars. Five allies spent two percent or more of their GDP on defence in 2016.
“It is realistic that all allies should reach this goal. All allies have agreed to it at the highest level and it can be done,” the secretary-general added.