Residents inspect the damage after airstrikes by pro-Syrian government forces in the rebel held Al-Shaar suburb in Aleppo, Syria, on Thursday. Picture: REUTERS/ABDALRHMAN ISMAIL

LONDON — The US demanded Russia immediately halt its bombing campaign in Syria on Thursday after a bitter breakdown in peace talks exposed the deep rift between world powers aiming to end the five-year conflict.

On the ground in Syria, President Bashar al-Assad’s forces made a breakthrough, entering two Shiite villages that had been under siege by rebels after also advancing around the city of Aleppo. Syria’s state news agency Sana reported "mass celebrations" in the streets of Nubl and al-Zahraa as people welcomed army troops and celebrated the breaking of the siege.

Peace talks in Geneva were suspended on Wednesday until February 25, with United Nations (UN) special envoy Staffan de Mistura saying "more work" was needed.

The suspension of the talks came as donors gathered in the British capital, aiming to raise billions of dollars in aid for Syria and to help its neighbours cope with millions of people that have taken refuge on their soil. The talks had been tipped as the most important push so far to end Syria’s bloody conflict, which has killed more than 260,000 people and forced half the country’s people from their homes.

French Foreign Minister Laurent Fabius accused Damascus and Russia of "torpedoing the peace efforts" in Geneva with the offensive. Russia has been launching air strikes in Syria, which it says are targeted at "terrorist organisations" such as Islamic State.

US Secretary of State John Kerry warned Moscow to halt its bombing of the Syrian opposition in what he said was a "robust" phone call with Russian counterpart Sergei Lavrov. "We discussed, and we agreed, that we need to discuss how to implement the ceasefire," Mr Kerry said.

UN secretary-general Ban Ki-Moon said the temporary pause in the talks showed "just how deep, how difficult the divisions are".

At the start of the aid conference in London, co-host British Prime Minister David Cameron urged a political transition away from Mr Assad in Syria, "however difficult that may be".

Before the talks, Britain pledged £1.2bn in aid to be spent until 2020 on what Mr Cameron called "the world’s biggest humanitarian crisis". German Chancellor Angela Merkel, under growing pressure over her open-door policy for refugees amid Europe’s biggest such crisis since the Second World War, pledged €2.3bn.

Some 4.6-million Syrians have fled to nearby countries — Jordan, Lebanon, Turkey, Iraq and Egypt — while hundreds of thousands have journeyed to Europe.

Jordan’s King Abdullah told the conference his country of 6.5-million people had "reached our limit" after taking 1.3-million refugees.

Lebanon’s education minister, Elias Bou Saab, told BBC radio that his nation of 4-million people had taken 1.5-million Syrian refugees.

"We have been dealing with an ongoing earthquake for the past four years," he said. "This crisis is going to grow, especially after what we heard yesterday when they postponed the peace negotiations."

As well as drumming up aid, the conference aims to allow more refugees to work in host countries and boost education.

In an editorial in the Guardian newspaper, Mr Cameron warned that a shortfall in UN funding for Syria "is fatally holding back the humanitarian effort".

"Last year, across the whole international community, only half of the money requested by the UN was raised," he said.

The UN is appealing for nearly $8bn, while regional governments are seeking an extra $1.2bn.

Organisers have already agreed that participants should at least "double" their contributions from 2015, when they raised $3.3bn.

Mr de Mistura’s brief at the Geneva discussions was to coax both sides into six months of indirect "proximity talks" envisioned under a November roadmap, but problems plagued his efforts from the start.

The Syrian opposition High Negotiations Committee arrived in Geneva several days late, insisting on immediate steps to allow aid to get through to besieged cities, a halt to the bombardment of civilians and the release of thousands of prisoners. Riad Hijab, committee co-ordinator, said late on Wednesday the group "will not return until the humanitarian demands are met or (we) see something on the ground".

AFP