Facing a shortage of experienced military personnel, the Canadian Forces has put out a call to retired veterans to sign up again -- not to battle, but to help train a new generation of soldiers.

While the military is exceeding its new recruit targets, the Afghanistan mission is draining the resources needed to get them into the system -- causing problems for the military's ambitious plans to boost its numbers.

Media reports say the Department of National Defence sent a letter in March to retired officers, asking if they would re-enlist because the Afghanistan mission has left Canadian Forces short of experienced trainers.

Lt.-Gen. Walter Natynczyk, the author of the letter, appealed to non-commissioned officers, captains and majors, to help fortify the Canadian forces for the future.

He wrote that the military isn't just looking to expand, but is "also facing greater demands for Canada to support more and more overseas missions while maintaining a healthy force within Canada to respond to domestic crises."

There are about 87,000 men and women who serve in the Canadian Forces as both regular force members and as reservists.

For the current recruiting year, which ends in the spring of 2008, the Canadian Forces hopes to add 6,425 new regular force members.

Defence Department officials tell CTV News they're already at about 36 per cent of that target. The department has exceeded its recruitment targets of about 6,200 new regular troops for each of the last two years.

But not only has the mission in Afghanistan left fewer leaders to train new recruits, it means there are fewer experienced soldiers to do long-range planning and make important equipment purchases -- vital tasks for the forces' future once the Afghanistan mission concludes.

"We've got a whole bunch of recruits that are keen coming into the military and they're needed," Maj.-Gen. (Ret'd) Lewis MacKenzie told CTV News. "But there are no instructors available to conduct their courses for them, so that's why it's critical to get instructors."

In the letter, Natynczyk wrote the forces are looking for trained professionals to "assist in a variety of ways in various locations and under a range of employment options."

MacKenzie said he believes many veterans will respond to the call to help solidify the future of the forces.

"So they're out there, and the country's at war, and they joined because they were patriots and therefore I wouldn't be surprised if this were attractive to them, and a fair number (of veterans) came back in for an extended period -- or even for a couple of years."

With a report from CTV's David Akin in Ottawa