A new report by the Parliamentary Budget Office says it's too early to tell if $1 billion is too much to spend on security for the G8 and G20 summits.

The Toronto G20 summit has few parallels in the world, Kevin Page said in his report. And comparing these summits' cost to those held in other nations is difficult because other nations have been unwilling to publicize their summits' true costs, the report said.

Still, the $930 million being spent on three days of meetings of international leaders is the largest sum ever spent on the summits.

The budget office's 12-page report, released Wednesday, shows costs have grown exponentially since Canada hosted G8 meetings in Kananaskis, Alta., in 2002.

The price tag per RCMP officer is estimated to be four times as high as in 2002, and for each national defence member the cost is three times as great, the report said.

Public Safety Minister Vic Toews said through his spokesman on Wednesday that "the overall costs won't be finalized until following the completion of the summits."

"The parliamentary budget officer's report is in line with everything we've said all along," including that the security costs are reasonable, spokesman Chris McCluskey told CBC News.

With files from the CBC's Leslie McKinnon