An Post is not attacking rural Ireland but putting in place a plan to ensure the future viability of post offices across the country, according to Chief Executive David McRedmond.
Mr McRedmond was reacting to criticism after the semi-state company announced that 159 post offices are to close as part of a deal with the Irish Postmasters' Union.
All the post offices facing closure are within 15 kilometres of at least one other post office.
Speaking on RTÉ's Morning Ireland, Mr McRedmond said An Post planned improvement for all customers using its services.
Mr McRedmond said the percentage of customers affected is 3.7%, while "96% of people will have better post office services".
"The 3.7%, we'd argue, would also have better post office services but they will have to travel a bit further. But 96% are completely unaffected.
"So, actually, we've done everything to make sure that rural communities, in particular, are well served. And that's what we're planning."
However, speaking on the same programme, Fianna Fáil communications spokesperson Timmy Dooley said: "Improving the services for some at a loss to others is not acceptable."
Mr Dooley said said there was an "encumbrance" on the State to support the post office network through the provision of a Public Service Obligation on An Post to retain the network at its current strength, supported through an agreed annual subvention.
"We have to be in a position as a State to provide an equality or an equivalence of service across the State, whether it's in urban or rural areas," Mr Dooley said.
The Chair of the Independent Postmasters' Group, Tom O'Callaghan has described the closure of 159 post offices as "absolutely devastating".
Speaking on RTÉ's Today with Miriam, Mr O'Callaghan said by closing these post offices, the heart of communities was being shut down as you were taking the economic activity out of an area.
Minister for Communications Denis Naughten has said it is important that Ireland has a viable post network across the country.
Speaking on the same programme, Minister Naughten said we have moved from a place, less than two years ago, where facing the closure of all post offices and the possible liquidation of An Post to the growth and expansion of the business.
He said there would still be 960 post offices across the country and that they would be able to provide foreign exchange services as well as the expansion of banking services.
He added that all of the post offices, bar one or two, would have access to high-speed broadband within the eight or nine months. He said digital services would also be increased within post offices.