Defense Secretary William S. Cohen, citing the increasing use of the Army National Guard and the Army Reserve, said yesterday he will not implement a scheduled cut of 25,000 reservists.

"Today the Defense Department cannot sustain operations anywhere in the world without calling on the National Guard and Reserve," Cohen said in a statement.

Cohen said his decision also took into account that Gen. Eric Shinseki, the new Army chief of staff, is reexamining the role of reserves in the Army and redesigning National Guard divisions.

"Any cuts . . . at this time could hinder these initiatives," Cohen said.

National Guard and Reserve members are participating in many overseas military operations, including peacekeeping missions in Bosnia and Kosovo.

The Pentagon determined in 1997, after a top-to-bottom review of its forces and defense priorities, that the Army should reduce its National Guard and Reserves by 45,000 people. An initial reduction of 20,000 was made, but Cohen has decided the additional cuts should not be made as scheduled.

The National Guard has 360,000 members, the Army Reserve 200,000. The active-duty Army totals 475,000.

Pentagon spokesman Kenneth Bacon said Cohen has notified members of Congress that decisions on possible additional reductions should not be made until the Pentagon completes a new top-to-bottom defense policy review, scheduled for 2001.