Deputy U.N. Special Envoy for Syria Ramzy Ezzeldin Ramzy met separately with regime and opposition delegations yesterday ahead of the formal start of a fifth round of peace talks in Geneva.

The U.N. on Tuesday urged those attending this week's Syria peace talks to engage "substantively and proactively."

"All invitees who had already attended the previous round of talks in February 2017 have confirmed their participation," de Mistura said earlier this week.

Among the previous attendees were delegates for the Syrian regime, headed by Bashar al-Ja'aafari, and representatives of the opposition, led by Nasr Hariri from the High Negotiations Committee.

Thursday's agenda was to focus on governance, constitutional issues, elections, security and confidence building.

De Mistura previously urged the participants to "do the necessary preparations in advance of the fifth round to be ready to engage substantively and proactively on the substance of all four baskets on the agenda in parallel."

The last round of talks began on Feb. 23 and ended on March 4 without any clear result.

Since the civil war in Syria erupted in March 2011, more than 250,000 people have been killed, according to the UN. The Syrian Center for Policy Research puts the death toll at more than 470,000.