"After nearly three painful years of conflict and suffering in Syria, today is a day of hope," Ban said when he opened the conference.
"Enough is enough, the time has to come to negotiate," Ban said in a closing press conference. "We must seize this fragile chance."
Syrian Foreign Minister Walid Muallem:
"If you want to speak in the name of the Syrian people, you should not be traitors to the Syrian people, agents in the pay of enemies of the Syrian people," Muallem said of the opposition.
"You spoke for 25 minutes," Muallem told Ban Ki-moon, when the UN chief complained that he had by far surpassed the 10 minutes he had been allotted to talk.
Syrian Information Minister Omran al-Zohbi:
"Assad will not go."
Ahmad Jarba, the head of the opposition Syrian National Coalition:
The conference should be "the preamble to Bashar al-Assad's resignation and his trial alongside all the criminals of his regime."
"How many years will Syrians have to wait in the face of the machine of death that is mercilessly mowing them down while the world sits on its hands?"
John Kerry, US Secretary of State:
"There is no way -- no way possible in the imagination -- that the man who has led the brutal response to his own people could regain the legitimacy to govern."
Russian Foreign Minister Sergei Lavrov:
"The negotiations will not be simple, they will not be quick," Lavrov told the conference, insisting the delegates had a "historic responsibility... to achieve an end to the tragic conflict in Syria".
French Foreign Minister Laurent Fabius:
"The situation is very difficult, we couldn't expect a bed of roses," Fabius said, accusing the Syrian regime delegation of being the only one that was "deaf and blind".
British Foreign Minister William Hague:
"We can be absolutely certain that if this peace process fails, then thousands more innocent Syrians will pay the price."
UN-Arab League envoy for Syria Lakhdar Brahimi:
"Do we go straight into one room and start discussing or do we talk a little bit more separately?... I don't know yet," Brahimi said, speaking about the aim of holding direct negotiations between the two warring sides starting Friday.