CALGARY -- Alberta's premier apologized Monday for the $45,000 it cost to go to Nelson Mandela's funeral in South Africa, but said she is not willing to repay the money.

Alison Redford says the amount caught her off guard, but the trip still falls under taxpayer-funded government business.

"It certainly has come to my attention that there were some decisions made that week without the full and complete information that we could have had, which didn't even follow our normal procedure in terms of trip planning," Redford said after a school funding announcement in Calgary.

"Mistakes were made. I accept responsibility for that and I apologize."

Redford has been criticized for not keeping a closer eye on the costs of the trip and the Opposition Wildrose party had demanded she repay the entire amount.

Redford was invited to be part of Prime Minister Stephen Harper's delegation in December.

"From my perspective this was a trip that was part of the Canadian delegation. It was business of the government of Alberta and I attended on that basis," she said. "I certainly take responsibility for the processes within place and I do apologize for that.

"It was very interesting for me to have the opportunity during that trip to have discussions with others who were on that trip with respect to work in Alberta. I do think it is part of the work a premier is asked to do."

Redford, who once worked with Mandela, made the journey with an assistant and indicated last week she wouldn't have gone to the funeral if she had realized how expensive it would be.

The premier and her aide took a provincial government plane to Ottawa at a cost of $15,000 to catch a free flight with Harper to South Africa. She and the aide flew home early on a commercial flight at a cost of $10,000 each to attend the swearing-in of her new cabinet.

Opposition leaders have noted that Nova Scotia Premier Stephen McNeil billed taxpayers less than $1,000 to go to the funeral.

They suggest that Redford's spending on trips abroad shows contempt for taxpayers, but she has said she will continue to travel to drum up business.