More than 100 members of Syria's opposition parties and rebel fighting groups are on board.
But news of a major Taliban attack in Afghanistan dimmed hopes of dialogue.
Advocates hope the meeting will move all parties closer to peace.
But diplomats played down the possibility that stalled Afghan peace talks might restart soon.
Truck bomb kills at least six people in Logar province, south of Kabul.
Peace talks between the Afghan government and the Taliban were suspended on Friday at the request of the Taliban.
The talk concluded with an agreement to meet again after the Muslim fasting month of Ramadan.
A senior Houthi member calls for negotiations to be overseen by "non-aggressive" parties.
The guerrilla rebels and the government agree to drop their uniforms and weapons in a step toward peace.
Leaders of Ukraine, Russia, Germany and France agree a deal to end fighting in Ukraine.
As peace talks begin in Belarus, the war continued to rage in Ukraine.
The guerilla group has invited the Colombian-born Miss Universe to peace talks in Havana.
The sides have held only one meeting since agreeing to a ceasefire in September.
France warned it would recognize a Palestinian state if talks stalled, and proposed a two-year timeframe to end the conflict through a U.N.-backed resolution.
Insiders say no breakthrough has been achieved with only 24 more hours of ceasefire left