The talks in Geneva aimed at ending the Syrian conflict look set to continue despite two bombings in Homs that killed dozens of people on Saturday.
Staffan de Mistura, the UN special envoy for Syria, says the attacks were a deliberate attempt to derail negotiations and he urged both sides to remain committed to the political process.
At least 42 people died in Homs when suicide blasts targeted military and intelligence buildings.
The government delegation says anyone who fails to condemn the attack is an "accomplice to terrorism".
But they are staying in Geneva and will meet de Mistura again on Tuesday.
Opposition negotiators also condemned the attack and said they would attend more talks this week.
But is a political settlement possible without involving all the armed groups?
Presenter: Hazem Sika
Hind Kabawat - member of the Syrian High Negotiations Committee (HNC)
Mohanad Hage Ali - director of communications at Carnegie Middle East Centre
Oubai Shahbander - international security program Fellow with New America Foundation
Source: Al Jazeera News