"COVID-19 has impacted the sustainability of community and regional publishing."
News Corp's major dailies, including the Herald Sun and The Daily Telegraph, will become more state focused, drawing content from regional and community journalists.
Larger regional papers, which includes the Hobart Mercury or NT News, will continue to be published.
The Wentworth Courier, Mosman Daily and North Shore Times, which Mr Miller says serve Sydney's "most affluent suburbs", will still be printed.
Some regional and community titles will no longer exist but their journalists will continue to feed copy into the local masthead.
In an email to staff seen by AAP, Mr Miller pointed to the coronavirus' impact on print advertising revenue for the changes.
He said there would have to be a fundamental shift in the way the company operated, including hiring digital only journalists and focusing on online advertising.
Media companies across the country are making massive cuts or shutting shop completely during the coronavirus pandemic, with the latest including Buzzfeed Australia and 10daily.
Media Entertainment and Arts Alliance chief executive Paul Murphy said Australian media was in crisis.
"The closure of so many mastheads represents an immense blow to local communities," he said.
The union was working to clarify exactly how many jobs would be lost, Mr Murphy added.