The Berejiklian and Morrison governments will split equally the cost of the bushfire clean-up, which is expected to run into the hundreds of millions of dollars.

Premier Gladys Berejiklian said the funding agreement was a "major breakthrough" ahead of a "massive" clean-up, which she expected to be largely completed within the next six months.

"We hope the bulk of the clean-up will be done by the end of June," she said on Monday.

"We know that's an ambitious target, but we're confident most people will feel some type of relief or some type of assistance in the clean-up process by that time."