NZR on Wednesday said "recent events" had forced the governing body to provide clarity on the appointment process and cited significant competition for talent in the global rugby market.
"Following wide ranging consultation and after carefully weighing up all scenarios and the key lessons from 2019, New Zealand Rugby is now commencing a process for selecting the All Blacks Head Coach from 2024," NZR chairwoman Patsy Reddy said in a statement.
"Noting the divergent views as to the best timings for this process and that neither timing window is perfect, out of respect for the people involved, New Zealand Rugby will not be making any further comment after today until a decision has been reached.
"This will be concluded in the next four to six weeks."
The statement comes three weeks after Scott Robertson, tipped to succeed Foster after the World Cup, said he was expecting an imminent announcement about his future in the New Zealand coaching structure.
Robertson lost out to Foster for the role when Steve Hansen stood down in 2019 but the success he has overseen at the Canterbury Crusaders has earned him plenty of coaching offers in other countries.
Reddy said Foster and the current All Blacks staff continued to have NZR's "full support" in this World Cup year.
Foster told New Zealand media last week that he might like to continue in the role if the All Blacks won the global showpiece.
On Wednesday, he said he would accept NZR's decision and move on.
"As I said last week, I felt the best thing for our team and for our entire management group was to have this process done after the Rugby World Cup," he said in a statement.
"My sole focus remains unchanged. It is to lead this All Blacks team and management group in our planning and preparation so that we go to France with the goal of winning the Rugby World Cup and making this country proud.
"I won't be re-applying for the job."
Foster was under intense scrutiny last year when the All Blacks suffered three consecutive defeats against Ireland and South Africa but NZR endorsed him as coach through to the World Cup following a review in August.
He subsequently guided the All Blacks to an eighth Rugby Championship title and an undefeated tour of the northern hemisphere at the end of last season.
