GENEVA, March 1 (Xinhua) -- The United Nations Secretary-General Ban Ki-moon on Friday urged both sides of the Syrian conflict to take the "very small window of opportunity" to hold talks to end the nearly two-year-old crisis.

Ban, who was here to attend the Human Rights Council's 22nd Session, told reporters he welcomed the proposal made by the opposition group to meet with representatives of the Syrian government and the willingness expressed by the Syrian government.

"This is a very small window of opportunity, which we strongly support and encourage them to use that. The opportunity may soon close," he said.

Ban added the situation in Syrian continued to deteriorate and that he was concerned about sectarian violence and spillover effects to neighboring countries.

"It is crucial to stop the violence, support Joint Special Representative Lakhdar Brahimi and start a political dialogue," he said.

He also said he would meet with Brahimi on Saturday in Switzerland to discuss on the situation of Syria.