BAGRAM AIR FIELD, Afghanistan — The Taliban failed to capture any ground from Afghan security forces fighting for the first time without foreign firepower this fighting season, US officials say, but the insurgents killed scores of soldiers, police, and civilians in their campaign to weaken the government.
American and NATO officials say the fledgling army and police aren’t ready to wage a sustained war against a determined insurgency.
Coming just 13 months before most foreign forces are to withdraw, the mixed results reported by US military officials underline the unresolved question of whether some of those forces should stay.
The assessment adds urgency to the need for the United States and Afghanistan to sign a much-delayed security agreement that will allow a residual foreign force to stay on after the Dec. 31, 2014, withdrawal deadline.
The United States says the one issue to be decided is which courts — US or Afghan — will prosecute crimes committed by American forces stationed here.
Washington is expected to keep about 10,000 troops in Afghanistan after 2014, provided the security agreement is signed and includes immunity from prosecution by Afghan courts.
NATO allies would provide about 5,000 troops, but only if an American presence remains. Billions of dollars in funds for Afghan forces and development also would be jeopardized if no deal is reached.
The 350,000-strong Afghan National Security Forces, made up mostly of the army and police, assumed responsibility for security in June, freeing the foreign forces to focus on training.
In so doing, it took the lead against an insurgency that had promised to recapture territory it has lost in the 12 years since the US-led invasion.
“Our efforts to date have enabled Afghans to assume the lead, take the fight to the enemy, and secure the population,” Marine General Joseph Dunford, the top US and coalition commander in Afghanistan, said in his fall update to the troops. ‘‘But our progress is not yet sustainable.’’
Holding territory came at a high price. Coalition officials say Afghan forces were at one point losing 100 men a week, mostly from roadside bombs.
The Afghans’ weakness, say military officials, is logistics — they have trouble with the upkeep of vehicles and other crucial equipment supplied by the West.
US Major General James C. McConville, who commands coalition troops in the volatile east near the Pakistani border, said Afghan forces there managed to hold territory as coalition forces began withdrawing in earnest.
Since March, he has closed 54 bases in the east, leaving just 11, plus a coalition presence at six Afghan facilities.
Coalition force levels have dropped from about 18,000 to less than 7,500 — nearly all tasked with training.