Remove object from array in Mongo

I have mongo documents like below and required to remove objects from Array. Required to delete object which doesn't have country attribute.

Before Unset:

{
   _id: 5150a1199fac0e6910000002,
   name: 'some name',
   items: [{
      id: 23,
      name: 'item name 23',
      country: 'ABC'

   },{
      id: 24,
      name: 'item name 24'
   },{
      id: 25,
      name: 'item name 26',
      country: 'XYZ'

   }
]
}

After unset :

{
   _id: 5150a1199fac0e6910000002,
   name: 'some name',
   items: [{
      id: 23,
      name: 'item name 23',
      country: 'ABC'

   },{
      id: 25,
      name: 'item name 26',
      country: 'XYZ'

   }
]
}