Sports venue has to admit US fans (7)
I believe the answer is:
stadium
'sports venue' is the definition.
(I've seen this before)
'admit us fans' is the wordplay.
'fans' is an anagram indicator (I've seen 'fanned' mean this (I've seen this in other clues)).
'admit'+'us'='admitus'
'admitus' is an anagram of 'STADIUM'.
'has to' is the link.
(Other definitions for stadium that I've seen before include "Sports arena" , "bowl?" , "Large structure for open-air sports" , "Admit us (anag) - sports ground" , "Sports ground as for athletics" .)