WASHINGTON - (AP) - President Barack Obama says valor andsacrifice in the armed forces are no longer defined by sexualorientation.

Obama spoke Wednesday morning at the Interior Department, wherehe signed a landmark law ordering America's armed services to letgay men and women serve openly for the first time. Surrounded bysenior military officials and members of Congress, Obama said he isproud to sign the bill, which he says will strengthen nationalsecurity.

The change won't be immediate, however. The bill requires themilitary service chiefs to complete implementation plans beforelifting the old "don't ask, don't tell" policy - and certify tolawmakers that it won't damage combat readiness, as critics charge.