Guterres' first visit as secretary general comes as the Afghan government faces internal turmoil, insurgents make gains nationwide and the international military coalition mulls plans to send thousands more troops to help struggling Afghan forces.
These combined threats have worsened the crisis for refugees and internally displaced people, forcing international bodies like the United Nations to call for emergency funding.
The crisis can only be solved by ending the war, said Guterres, standing in a makeshift camp on the outskirts of Kabul that accommodates Afghans displaced by fighting.
"Peace is the solution for the problem," said Guterres, previously a United Nations' high commissioner for refugees.
At least 126,000 Afghans have been forced to flee their homes, the United Nations says.
More than 218,000 Afghan refugees have also returned this year.
The International Organization for Migration estimates that at least 600,000 refugees could return this year, piling strain on aid groups struggling to help the newly displaced.
Khumri, a 30-year-old Afghan woman who met Guterres, said she had lived in the squalid camp for the last two years with her family after their home was destroyed and her husband killed in the northeastern province of Kapisa.
"We need everything," she said, recounting the struggle for clean water, food, and hygiene materials that drives some to beg.
Guterres was set to meet Afghan President Ashraf Ghani, who is trying to soothe domestic political tension after recent violence in the capital, Kabul.