The head of the Syrian opposition’s negotiating team said the upcoming peace talks brought no hope, casting further doubt on whether the group will attend meetings planned for Friday in Geneva.

According to Arabic news channel Al-Hadath, Assad al-Zoubi said that recent diplomatic moves “did not give cause for optimism over the negotiations”.

He added that the United Nations special envoy for Syria, Staffan de Mistura, “cannot impose conditions” on the opposition team.

The High Negotiations Council (HNC) was due to meet in Riyadh later on Tuesday to decide whether to attend the Geneva session.

The council has already stated that the opposition would only take part in the session on condition that air strikes by the Syrian government and its Russian allies be halted and sieges on towns be lifted.

De Mistura has said the Geneva meeting will aim to initiate six months of talks, first seeking a ceasefire, then working towards a political settlement to a ravaging war that has left more than 250,000 people dead and more than 10 millions seeking refuge around the world.