Mortuaries where America is forced to keep rubbish back (10)

'mortuaries' is the definition.
(crematorium is a kind of mortuary)

'america is forced to keep rubbish back' is the wordplay.
I cannot really understand how this works, but
'america' could be 'a' (common abbreviation - e.g. in organisation names) and 'a' is located in the answer.
'to' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

'where' is the link.

Can you help me to learn more?