The former test loose forward has enjoyed huge success at the Canterbury Crusaders and was lined up to replace Foster when the All Blacks hit a form slump last season.
Foster's job was saved when New Zealand beat South Africa at Ellis Park in August but Robertson said he expected some public announcement of the succession plan from New Zealand Rugby (NZR) before the start of the Super Rugby season.
"It's one of those times I'm just waiting for NZR to make the announcements really," Robertson told reporters at the Crusaders' home ground in Christchurch on Wednesday.
"Hopefully we know in the next few days."
New Zealand Rugby appeared to be caught on the hop by Robertson's comments and later released a statement saying "an announcement about the All Blacks' head coach or process is not imminent".
NZR's next board meeting is on February 23rd, a day before the Crusaders kick off the new season against the Waikato Chiefs.
The Crusaders have won a Super Rugby title of some description in each of Robertson's six seasons in charge at the south island powerhouse.
The former New Zealand Under-20s coach lost out to Foster for the All Blacks job when Steve Hansen stood down in 2019 but the success he has overseen at the Crusaders has earned him plenty of offers of coaching roles in other countries.
"I've had options, but I've always said, my preference is to be here in New Zealand and coach my country," Robertson added.
"I’ve also been really patient. I think where we are now, that's what we're going to deal with, not what's has happened ... the next two weeks is big."
Japan coach Jamie Joseph (53) is another possible candidate to replace Foster when his contract runs out after the World Cup, although a fourth triumph for the All Blacks at the tournament in France could force a revision of plans.
