Vault signed-ssh-certificates - How to use the signed key in "Apache Ant" script

In the terminal, I can connect to the remote host using the vault signed key.
But could not authenticate via ant scripts.

Sample script:

<sshexec	host="${server.host}"
 			username="${server.userid}"
 			keyFile="/var/jenkins_home/.ssh/id_rsa"
 			failonerror="true"
 			command="mkdir -p ${deploymentLocation}" trust="yes"/>

Error : com.jcraft.jsch.JSchException: Auth cancel

Can I have anyone support to resolve this?