NATO announced on Tueday it is scaling back joint operations with Afghan security forces in the wake of an increasing number of insider attacks which have killed 51 NATO troops this year.

"In response to an increased threat situation as a result of the 'Innocence of Muslims' video, plus the recent insider attacks, ISAF forces are increasing their vigilance and carefully reviewing all activities and interactions with the local population," said Maj. Lori Hodge, a spokeswoman for NATO's International Security Assistance Force.

"We adjust our force protection measures based on the threat. If the threat level goes down, we could see a rolling back on this decision."

A senior NATO spokesman, U.S. Colonel Tom Collins, said the measure "will apply only until the threat level returns to a tolerable level."

A NATO statement indicates that there would still be some partnering between Afghan and NATO forces.

“Most partnering and advising will now be at the Kandak (Battalion) level and above,” ISAF said in its statement.

“This does not mean there will be no partnering below that level -- the need for that will be evaluated on a case-by-case basis and approved by RC (regional) commanders."

A Reuters report adds:

The scaling back of cooperation could also complicate tense negotiations between Washington and Kabul on a deal to keep some special forces and trainers in the country after 2014, a sensitive topic for Afghans embittered by continued civilian deaths and more than a decade of war.

Officials from both sides had hoped to conclude a deal by early next year, but Afghan President Hamid Karzai this week accused Washington of breaching previous security agreements underpinning the talks.

Karzai's office also denounced a NATO weekend air strike in which at least eight women collecting firewood were killed east of the capital.