"I don't think anyone would argue that I'm not available."
She said she has appeared in eight press conferences and 21 interviews over the last week. But she said she intends to spend more time with different media outlets.
She said her "looking to reach more people" was not to do with doing more Facebook lives.
Earlier today, Hosking said the Government was "over being held to account".
"She no longer wants to be on this programme each week. The somewhat tragic conclusion that is drawn is the questions she gets, the demand for a level of accountability ... [is] a little bit tough," he told listeners this morning.
A statement from the Prime Minister's office to Newstalk ZB said: "The Prime Minister's schedule of media appearances has been reviewed and while it hasn't reduced overall, it has changed.
"The Prime Minister will no longer do a weekly slot specifically on the ZB morning show.
"However she, and all her ministers, will continue to appear on the show as and when issues arise."
Ardern's decision to step away from her regular slot with Newstalk ZB is a bold move, with the regular segment on air for more than 30 years.
Newstalk ZB's Paul Holmes was the first host of the regular segment with New Zealand's prime ministers, interviewing various leaders on the show over the years starting in 1987.
David Lange was the prime minister at the time the segment started.
However, it's not the first time a prime minister has declined to appear regularly on a segment with a New Zealand broadcaster.
In 2011, John Key repeatedly turned down a number of interview requests with RNZ's Morning Report.
