GENEVA (AP) — Women and children trapped in a Syrian city under government siege will be permitted to leave as soon as Sunday under a deal that marked the first tangible — if limited — sign of progress in peace talks.

Lakhdar Brahimi, the mediator brokering the negotiations, acknowledged that the agreement on the city of Homs fell short of his hope to send a humanitarian aid convoy. But, he said, “To bring Syria out of the ditch in which it has fallen will take time.”

Homs, one of the first cities to rise against President Bashar Assad, once more came under mortar attacks from the government.

Brahimi defended the pace of the talks, which have yet to touch upon the issue of Assad’s future.

“I think being too slow is a better way than going too fast,” he said. “If you run, you may gain one hour and lose one week.”

Brahimi said the thorniest topic — a possible transitional government — will not come up until at least Monday.

“I think this belittles the importance of this conference and the goal that was drawn for it,” said Bouthaina Shaaban, an adviser to Assad.

The Western-backed opposition, made up largely of exiled Syrians, says Assad has lost legitimacy and can no longer lead a country after unleashing the military on largely peaceful protests nearly three years ago.

The government says the rebellion is rife with terrorists and that Assad is the only person able to end the fighting that has killed more than 130,000 people.

In the meantime, the homegrown rebellion has become a regional proxy war between Iran and Saudi Arabia, with foreign fighters flooding in on both sides.

Homs was considered a promising place to start the negotiations.

The city was one of the first areas that plunged into armed conflict in 2011. Neighbourhoods in the old city have been ravaged following repeated government assaults to reclaim control from rebels.

The city had a pre-war population of 1 million, but most residents have since fled. Activists say about 800 families are trapped, without regular access to food, medicine and basic necessities.

“The regime is blocking all convoys to Homs and has been doing so for months,” said a senior US official, speaking on condition of anonymity because the talks remain sensitive. “The situation in Homs is extremely urgent. Anything the government says to the contrary is false.”