KANDAHAR, Afghanistan - They are supposed to be our exit strategy.

But the latest Canadian government quarterly assessment raises concern about the number of soldiers leaving the Afghan National Army, which is expected to take over security in key Kandahar districts by next summer.

Although the high attrition rate among Afghan soldiers has always bothered Canadian and NATO mentors, the challenge of recruiting, training and keeping those soldiers has started to weigh more heavily as Canada prepares to wind down its military mission in Afghanistan in 2011.

The report, released late Wednesday in Ottawa, said the benchmark of a capable security force "continues to be challenged by issues relating to attrition, retention and recruiting."

Another battalion, or kandak, of Afghan soldiers under Canadian guidance has reached its top-tier status. That makes two battalion-sized units ready to go, but the report said they're undermanned and the ranks looked thin last fall.

"Leave granted to soldiers around the Eid holiday and following the presidential elections likely contributed to decreased (Afghan National Army) capacity in this quarter," said the quarterly report, which covers the period up to the end of 2009.

"Until targeted ANA growth is realized, benchmarks for shouldering the security burden and leading security operations will continue to be a challenge."

Neither of the two battalions were operating at 70 per cent strength, which is Canada's benchmark goal.

More Afghan troops are being linked with U.S. units for training and that has meant a decline in the number of operations conducted with Canadians.

It's a sign the Afghans don't yet have enough troops to go around.

The overall Afghan army is reporting an attrition rate of about 18 per cent, according to figures released by NATO. It's not clear what the rate is like for units in the south, where most of the fighting is taking place.

Officers with the Canadian-led Task Force Kandahar were not immediately available for comment Thursday.

The quarterly report noted a recent 40 per cent pay increase -- to US$165 a month per enlisted soldier -- has "stimulated recruiting."

The U.S. general in charge of the combined army-police training command in Afghanistan acknowledged last week that high attrition rates were hampering efforts to build security forces.

Lt.-Gen. William Caldwell told a NATO briefing that he has begun to wonder if the allies would reach their goal of expanding the Afghan army to more than 170,000 soldiers by October 2011. A longer-term goal is to reach 240,000 soldiers and 160,000 police within five years.

In September, only 880 young Afghans signed induction papers but by December that figured had jumped to 7,800.

Caldwell attributed the 800 per cent increase to the pay hike, which was also extended to the police.

"Whether you serve in the Afghan National Police or in the Afghan National Army you have pay parity and rank and longevity pay, which is a very positive step forward," he said after briefing NATO's council on March 3.

Putting cops on par with soldiers in terms of pay is seen as a way to combat deep-rooted corruption within police ranks. The Afghan National Police suffer from an even worse attrition rate of 25 per cent.

Low morale has allowed the Taliban to infiltrate police ranks. Five British soldiers were murdered by a rogue Afghan policeman last summer.

In order to beef up security, Caldwell said new Afghan recruits are required to submit to a biometrics scan and background check before they are trained.