Problem with the AIC from surival model with exclusively created survfit() function

Question

Why is not possible to extract the AIC from this model:

surv_object <- Surv(time = data$`Last observation (days)`, event = data$Death)
surv_object 
fit1 <- survfit(surv_object ~ Treatment, data = data)
summary(fit1)

AIC(fit1)
Error in UseMethod("logLik") : 
  no applicable method for 'logLik' applied to an object of class "survfit"

Thanks