Can / Should you make a toddler apologise?

[mezzer]

My dd (21mo) is in the "hitting" phase. Hits other kids if she doesn't get her way, wants a toy, etc and sometimes for no apparent reason at all. I grab her hand, firmly say "No hitting. We do not hit!" remove her from the situation. Give her a talking to (we don't hit. hitting is not nice. need to be gentle. bla bla bla) and then say "You need to say you're sorry." Sometimes, she agrees and goes and says sorry (her version of the word plus a stroke on the arm). Sometimes, however, she outright REFUSES to apologise. Should I insist? At times, I've tried insisting but make no headway (she is STUBBORN beyond belief). So, my questions - should I force her to apologise? If so, how to get her to do it when she refuses... Or, is it unnecessary and better if I just apologise for her (give other child attention, etc).

also, there is no need to accept a smirky sorry, i make them sound sincere as part of the deal (obv not at 21 months!)
as others have said, i would try to get them to apologise, if they won't then i make a big fuss of poor victim, say sorry on my kid's behalf, take my ds home and tell them off some more at home. but at 21 months I wouldn't be too harsh.