UN hopes US-Russia talks on Syria 'reach outcome'

Negotiations between senior US and Russian officials aiming for a broad ceasefire in Syria are likely to last into the weekend, as the conflict only intensifies further, the United Nations Special Envoy for the Syria crisis, Staffan de Mistura, said on Thursday.

Military, security and diplomatic officials from the US and Russia resumed talks in Geneva on Wednesday to give a "renewed and solid momentum to the cessation of hostilities", the UN Special Envoy said.

Their talks follow a marathon meeting between US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov who failed to reach a deal last week.

The two negotiations reflect a desperate diplomatic effort to bring some peace amid an escalation of the five-year conflict, both in Aleppo and elsewhere in Syria.

In a separate negotiation, there was still hope of agreeing on a regular 48-hour truce in the divided northern city of Aleppo to allow aid deliveries and medical evacuations, de Mistura's humanitarian adviser Jan Egeland said.

De Mistura said: "The discussions currently taking place between the US and Russia at a very high level and operational level go well beyond the 48-hour pause (in Aleppo)."

Egeland said only pressure from countries including Iran, Saudi Arabia and Turkey could unlock the door to aid deliveries.

Last week the long-besieged rebel-held town of Daraya surrendered in a deal with Syrian regime-backed forces.

De Mistura said there was clearly a Syrian regime strategy to achieve similar deals in other besieged towns, which Egeland said were making "urgent pleas" to have their sieges broken.

Kerry, Lavrov speak on phone

Russian Foreign Minister Sergei Lavrov had a conversation on the phone on Thursday with US Secretary of State John Kerry and discussed cooperation in Syria, the Russian foreign ministry said in a statement.

Last week, the two officials said they still have issues to resolve before an agreement could be announced.

Teams from both sides would try to finalise details in the coming days in the Swiss city, they said.

Kerry said the talks with Lavrov had "achieved clarity on the path forward" but together they offered few details on how they planned to renew a February cessation of hostilities and improve humanitarian assistance.

"We don't want to have a deal for the sake of the deal," Kerry said. "We want to have something done that is effective and that works for the people of Syria, that makes the region more stable and secure, and that brings us to the table here in Geneva to find a political solution."