The number of people who may get a delayed cancer diagnosis as a result of Covid-19 is not known.
The Health Service Executive (HSE) says it has not quantified the knock-on effect of screening services being closed for two months.
Screening for cervical, bowel and breast cancer stopped on March 27.
The Health Service says it has not quantified the potential delayed diagnoses as a result.
Chief Clinical Officer Colm Henry says estimating a time for a resumption of screening services is not possible.
He says: "If you ask me is there a date for starting up the program the way it was before Covid I can't say that.
"And there is different plans looking at volume, the type of screening test, focusing on high priority groups."
The model of screening -when it does resume- is likely to change drastically to allow for social distancing.
HSE CEO Paul Reid says a plan on how to resume all non-essential procedures -including screening services- will be finalized in the next week.
He says: "It will be phased and it will be clinically prioritised and guided by the public health measures that we monitor."
The HSE says the priority is a focus on increasing the number of people with cancer symptoms being referred through their GP to rapid access clinics.