UN Chief Ban Ki-moon late Thursday expressed disappointment that the two rounds of the Geneva II Conference failed to reach a political solution to the conflict in Syria, and said pessimism cannot prevent the international community from continuing its efforts."I am disappointed that two sessions of the political negotiations have not brought good progress, but we should not be overly pessimistic," Ban told reporters in answer to a question. "We have to continue. There is no other option but to continue this Geneva Conference. That is what I am emphasizing and I have been continuously discussing this matter with (Joint Special Representative) Lakhdar Brahimi and I will continue to do that," he said.In the meantime, he added, "I urge the international community to provide humanitarian assistance" to the millions of Syrians inside and outside the country."We have to support them, but what is most important is that we have to address this fundamental root-cause of the problems and we have to address the political challenges through Geneva II Conference," he stressed.