The United Nations and Syria have reached a deal to allow civilians to leave areas of Homs under army siege for more than 18 months, the provincial governor said Thursday.

"A deal has been secured with the United Nations, under which civilians will be guaranteed an exit from the Old City neighbourhoods very soon," state news agency SANA reported, citing governor Talal Barazi.

The statement came days after regime and opposition representatives meeting for peace talks in Geneva discussed the situation in the besieged districts of the central city.

UN-Arab League envoy Lakhdar Brahimi had announced that Damascus agreed to allow women and children out, though the opposition and the regime then accused each other of blocking any further progress.

There had been no deal on the exit of men, or the entry of much-needed aid into the city, where activists say some 3,000 people have been surviving on little more than olives for many weeks.

The Old City districts of central Homs have also suffered near-daily shelling ever since the army blockaded them in June 2012.