The announcement, communicated to Mr Brahimi by the Syrian government, is a rare advance in peace talks that have struggled to make much progress.
On Sunday face-to-face talks between negotiators from the Syrian government and the opposition Syrian National Coalition broke down because the parties disagreed over basic facts.
The two parties had been discussing prisoner releases and access for humanitarian aid – but broke off the discussions and instead entered separate preparatory discussion with Mr Brahimi ahead of political talks tomorrow.
However, Mr Brahimi announced that the Syrian government had told him that “women and children at least in this besieged city of Homs are welcome to leave.”
The Syrian opposition is seeking the release of 50,000 detainees, and Mr Brahimi said he had asked for lists of these detainees to be provided by various armed groups in Syria.
The UN mediator will meet with the two sides of Syria’s civil war again on Monday, in face-to-face talks aimed at exploring a political solution to the crisis.
He said he expects a “general statement about the way forward” to be made by both sides at some point on Monday.