Geneva talks
UN mediator for Syria, Staffan de Mistura speaks during a news conference on the peace talks outside the President Wilson hotel in GenevaDenis Balibouse/Reuters

Peace talks aimed at ending almost five years of civil war in Syria have broken down after just two days, as Bashar al-Assad's army advanced in Aleppo. The Geneva peace talks, which began on 1 February, have now been "paused" by the UN after a lack of progress.

UN envoy Staffan de Mistura had described the high level talks as the last chance to bring about an end to the conflict, but decided to restart the talks on 25 February. The envoy added that it was not the end of a peace deal, but "more work needed to be done" before they sat down again.

Members of the main Syrian opposition group – known as the High Negotiations Committee (HNC) – and representatives from Bashar al-Assad's government are in Switzerland as the war rages on in Syria. According to reports, government forces had broken a three-year siege on the mainly Shia towns of Nubil and Zahra.

The government's territorial breakthrough and severing of key supply lines for the opposition came after hundreds of raids by Russian bombers. According to the UN, attacks have increased persistently in the last few days.

The British-based Syrian Observatory for Human Rights reported that more than 750 fighters from the al-Qaeda affiliated al-Nusra Front were fighting in northern Aleppo, with shells raining down from both government and rebel lines. The Levant Front rebel group, also fighting in Aleppo, said that over 500 bombing raids had taken place in, what was, Syria's most populous city.

The civil war in Syria has claimed the lives of more than 250,000 people, with a further 11 million people fleeing their homes. The HNC wanted sieges in Syria lifted and prisoners released, while the Syrian government was repeatedly asking for a written agenda for the talks and a full list of participants – despite continuing their military operations.

Staffan de Mister was quoted by Reuters as saying: "I have indicated from the first day that I won't talk for the sake of talking. I have concluded frankly that after the first week of preparatory talks there is more work to be done, not only by us but by the stakeholders."

Attendees in the opposition delegation were angered at offensives by the Syrian government –backed by Russia – as peace talks were underway. Basma Kodmani, a member of the umbrella group HNC, said the Aleppo advance amounted to his belief that "there is nothing to negotiate - just go home".