Syria peace talks 'temporarily halted' as Assad forces advance on Aleppo backed by Russian air strikes

The offensive has cut off rebel supply lines and disrupted humanitarian aid, according to US State Department officials

Pro-government soldiers in the town of Tal Jabin, north of Aleppo, ahead of the assault to recapture Nubul and Zahraa (Getty Images/AFP)

Syrian peace talks have been “temporarily halted” because of a major advance by Assad forces against rebel forces north of Aleppo.

The government advance - which was backed by Russian air strikes - has choked opposition supply lines from Turkey to the city and disrupted humanitarian aid, a US State Department official said.

The advance saw the army break a three year siege of two government controlled towns in the area - Nubul and Zahraa - which were previously surrounded by opposition territory.

Speaking at a news briefing, the state department spokesman John Kirby said the talks - which officially began two days ago in Geneva, Switzerland - did get under way before the new Syrian army assault on Wednesday.

He said the assault was mainly focused on opposition forces and urged Moscow to focus on routing out Isis.

UN envoy Staffan de Mistura, who suspended the talks, said they will resume on 25th February, adding “this is not the end, and it is not the failure of the talks” and insisted both sides were “interested in [getting] the political process started”.

But the Syrian government’s UN ambassador Bashar al-Ja’afari accused the opposition of pulling out of the talks because it was losing the fight on the ground.

He said: "The military developments on the ground were crucial. Notice that the [opposition] decision of withdrawal came after opening the road to Nubul and Zahraa".

Nubul and Zahra have been blockaded by rebel groups for around three years, with the army occasionally dropping food and other aid by air.

Their capture marks a major victory for government forces, which have made significant advances in Aleppo province in the past few days.

Basma Kodmani, a member of the opposition's negotiating team, described the offensive as a "horrible development," saying it sends the message that "there is nothing to negotiate. Just go home."

Mr De Mistura said both sides had expressed concerns about the talks, with the government wanting to address "procedural issues before talking about [the] humanitarian side."

But he said "the UN cannot allow simply procedural matters to become more important than the result for the humanitarian situation for the Syrian people, who have been waiting for us to deliver... something concrete for them."

The talks are aimed at ending the five year long civil war between the Assad government and rebel groups which has killed more than 250,000 people and displaced 11m more.

Isis and fellow Islamist group Jabhat al-Nusra have not been included.

Additional reporting by agencies