"He is a great man, and he redefined this province. And his legacy is important," Redford told reporters following a luncheon speech Wednesday.
"This is the time to talk about that legacy, but right now not too much.
"Right now we have to respect the fact that the family is going through very difficult times."
Klein, 70, is in a care home in Calgary battling a form of dementia and a lung disorder.
Klein was the Progressive Conservative premier from 1992 to 2006 and was the mayor of Calgary before that.
On his watch, Alberta became debt free by paying off $23 billion. But Klein was criticized for focusing too much on the debt and not building enough roads, schools and hospitals for the hundreds of thousands of newcomers who arrived during the oil boom last decade.
Calgary's current mayor, Naheed Nenshi, said Tuesday that Klein and his family are in his thoughts and prayers.
"To me he'll always be the mayor who is best identified with this city," Nenshi told Global Calgary.
NDP Leader Brian Mason, a longtime question period foe of Klein's, also wished the former premier well.
Mason said the two didn't agree on much, but Klein has such a disarming personality, you can't help but like him.
"He was a hard guy not to like. He was charming," said Mason.
"I described him one time as (kind of like) a cute little puppy right next to a pile of poop on the rug — you didn't know what to do with him."
Wildrose Leader Danielle Smith said she remains optimistic.
"He has had tough times before and he's recovered from them, so our hopes and prayers are with him that he does make a recovery and he is able to have a few more months with his family," said Smith.
Liberal Leader Raj Sherman called Klein “a force to be reckoned with.”
“He was animated and fiery, and his passion for politics and Alberta serves as an inspiration to me and my colleagues,” said Sherman in a news release.
Even seven years after he left office, Klein remains a popular and polarizing figure.
Both right-centre parties in Alberta's legislature lay claim to being his philosophical standard bearers.
Redford's Progressive Conservatives point out Klein is a fellow PC.
Smith's Wildrose, however, say Klein's trademark debt reduction beliefs dovetail with their political philosophy and not with a Redford government that is borrowing billions of dollars to build roads, schools, and hospitals.
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