There has been a four-fold rise this year in the number of people killed in the conflict in Afghanistan, according to a report on the insurgency.
There has been significant Taleban activity in Paktika in recent months
It suggests that more than 3,700 people have died so far this year - about 1,000 of them civilians.
The report came as Afghan officials said Nato and Afghan troops had killed about 60 Taleban fighters.
Meanwhile a visiting UN delegation said Afghan leaders face huge challenges five years after the Taleban fell.
The study on the situation in Afghanistan was compiled by the Joint Co-ordinating and Monitoring Board - made up of the Afghan government, its key foreign backers and the UN.
It says more than 3,700 people had been killed since January this year and that the frequency of insurgent or terrorist-related security incidents had now risen four-fold to 600 a month.
The BBC's Matt Prodger in Kabul says the accuracy of fatality figures is hard to gauge, as they are frequently the result of aerial surveillance.
The majority of the dead appear to be insurgents, but it is estimated that 1,000 civilians have also been killed this year, along with members of the Afghan army, the Nato-led international security assistance force, and a separate US contingent of soldiers.
The deteriorating security situation has undermined vital development work and forced the closure of schools in the south.
The report also highlights corruption and says that alienation among the Afghan people is hampering those fighting the insurgency.
The head of the visiting Security Council delegation, Japanese ambassador Kenzo Oshima, told reporters in Kabul that the most important challenge was the fight against the Taleban insurgency, and that opium production, which was fuelling the violence, was also a major problem.
But he added that the international community would continue to support Afghanistan in its efforts towards peace and reconstruction.
The delegation is due to visit the troubled southern provinces in the next few days.
Afghan officials said the bodies of 20 Taleban militants had been recovered after recent fighting in Bermel district in Paktika, where a six-day operation by Nato and Afghan troops ended on Sunday.
In addition, two trucks carrying Taleban fighters were destroyed by artillery or aircraft fire. Another 40 were thought to have been killed in these attacks, the officials added.
Nato spokesman Luke Knittig could not confirm the casualty figures but told the Associated Press news agency the figure of 60 dead sounded "about right".