United Nations Secretary General Antonio Guterres (C) visits a camp for internally displaced people outside Kabul, Afghanistan June 14, 2017 - Reuters

KABUL: There is no military solution to the conflict in Afghanistan that is forcing record numbers of people from their homes, United Nations Secretary General Antonio Guterres said on Wednesday, during an unannounced visit to the war-torn country.

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 from neighbouring Iran and Pakistan, many citing pressure from authorities there.

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 by government forces battling Taliban occupying their village 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.

Ghani also hosted international delegations last week in a bid to set the stage for peace negotiations with the Taliban, which have remained stalled amid widespread fighting.

If the Taliban do not begin negotiations soon, Ghani will seek new UN sanctions against the group as a sponsor of terrorism, he told the June 6 meeting.

Any sanctions would be up to the UN Security Council, Guterres said. Afghanistan has endured too many "foreign interventions", however, he added, urging an eventual deal to resolve the war.

Thousands of international troops remain in Afghanistan to train and assist Afghan forces, besides mounting counterterrorism operations.

US President Donald Trump has given Defense Secretary Jim Mattis the authority to set troop levels in Afghanistan, opening the door for future troop increases.