WASHINGTON, April 16 (Xinhuanet) -- The US Defense Department has approved the extension of duty in Iraq for some 20,000 American soldiers when the military has seen a drop in the retention rate among soldiers whose enlistments were ending or who were eligible to retire.

    Through March 17, nearly halfway through the fiscal year, the Army fell about 1,000 short of meeting its goal of keeping 25,786 soldiers, a USA Today report said Friday.

    The retention rate of 96 percent was lower than last year's 106percent, when more solders stayed than the Army had planned, the report said.

    Full-time soldiers and members of the Guard and Reserve could choose to leave instead of stay this year because of the strains of service, including longer and more frequent overseas missions, military personnel experts warned.

    Defense Secretary Donald Rumsfeld said Thursday that the Defense Department would extend stay in Iraq beyond one year for about 20,000 soldiers who are scheduled to rotate out of the country. Their time in Iraq will grow as much as 90 days.

    The extension comes after two weeks of violence in Iraq including the kidnappings of some foreign nationals and deadly attacks on American soldiers.

    There are 137,000 US troops in Iraq, and there were plans to reduce the number to about 105,000 this summer. But Rumsfeld said Thursday that he could make no guarantees about future troop levelin Iraq. Enditem