There's no need to worry.
There is no cause for undue alarm.
There's no need to worry.
You don't need to worry anymore.
You don't have to hurry.
You don't need to worry about it.
You need not worry.
心配ないです。
You don't have to be so nervous.
心配ない。
You don't have to trouble yourselves.
You can bet your boots on that.