"Toronto has been a very useful summit already to help push people to make some decisions and restrict the range of discussion on what that definition (of capital) is," Carney said earlier this week.

"We're making serious progress on capital," he said, adding that he expected the group to sign off on a deal by the November summit of G20 countries.

Leaders from the Group of 20 emerging and advanced nations kick off two days of talks Saturday evening in Toronto, with tougher rules for banks high on the agenda as they seek ways to prevent another round of taxpayer-funded bailouts in the future.

"All systems are going to have to build up more capital and I think we are going to move to a common agreement on what that capital is and what the level needs to be by the Seoul summit in November," Carney said.

If countries get their banking rules right, with a focus on stricter capital, liquidity and leverage rules, then there is no need for a bank tax.