OIF Fedlet error Cannot run program "keytool": error=2, No such file or directory

$JAVA_HOME/java -classpath WEB-INF/lib/opensso-sharedlib.jar:WEB-INF/lib/openfedlib.jar:install/lib/configurefedlet.jar oracle.security.fed.fedlet.install.ConfigureFedlet

Error
Cannot run program "keytool": error=2, No such file or directory


Solution:
I have resolved this error by specifying

export JAVA_OPTS="-d64"

along with other commands to export JAVA_HOME and PATH