The US Army has offered shorter tours of duty to new recruits as a way to bump up enlistment.

Army officials say recruits may sign up for 15 months of active duty, rather than the customary four-years . They would then have to serve two years in the Army Reserve or National Guard, and seven years in the Individual Ready Reserve.

It is hoped that these and other inducements will reverse what US Maj. Gen. Michael Rochelle has called "the toughest recruiting climate ever faced by the all-volunteer Army."

Since 1973, the US armed forces had depended solely on volunteers to fill its ranks. Of the 80,000 active-duty soldiers the Army needs to recruit this year, less than half totalling 35,962 have signed up.

Experts blame the shortage on several factors, including the war in Iraq and efforts by family members and friends to dissuade recruits.

Some information for this report provided by Reuters.