International Syria mediator Lakhdar Brahimi said Thursday he has no plan to return to Damascus and gave a guarded response to an offer by an opposition leader for talks with government figures.
"It is worthy of note," Brahimi said of a statement by Syrian National Council leader Moaz al-Khatib that he was "ready for direct discussions" outside of Syria.
But the UN-Arab League envoy said the reaction of the government and other opposition figures would be crucial.
UN leader Ban Ki-moon also welcomed the offer by Khatib but said the conflict levels are already "intolerable."
Brahimi and diplomats have noted that Khatib has set major conditions such as the release of 160,000 detainees held by President Bashar al-Assad's forces.
Amid general gloom about prospects for a negotiated end to the escalating 22-month old war, Brahimi said he would not return to Syria unless developments change.
"If I go to Syria, it's because there is something that I need to do," he told the UN News Service.
Brahimi this week urged the UN Security Council to end its wrangling over Syria and unite to force talks to end the conflict which the UN says has left more than 60,000 dead.
The veteran envoy said that political talks had to be pursued as the fighting worsens.
"Our efforts at starting negotiation have not been very successful. But the military campaigns have not been successful either in finishing the conflict," he told the UN agency.
"Nobody has said it's going to be easy," he added. "But perhaps negotiating is better than killing each other."
Brahimi again called on the Security Council to unite and use a statement agreed by the major powers in Geneva on June 30 as a basis to force a political transition.
The statement -- agreed by Russia, which has blocked three UN Security Council resolutions on Syria, and the United States -- calls for a transitional governing body with full executive powers.
Russia says Assad cannot be forced to stand down. The United States and the Syrian opposition say the president cannot take any role in the process.
Brahimi said that the Geneva statement remains a basis for a political solution, but stressed divisions among the Security Council permanent members -- Russia and China on one side and the United States, France and Britain on the other.
The permanent powers must come to "a common understanding of what Geneva meant," said Brahimi, whose frustrations with the Security Council were shared by the last Syria envoy Kofi Annan.
"I think they can make the Geneva agreement operational," he said. "I think they could do that if they speak in one voice."
In his comment on the Syrian opposition offer, Ban said he welcomed the move but joined with Brahimi in stating that "the levels of suffering and destruction in Syria are already intolerable," said a UN spokesman.
Ban and Brahimi called for "a credible process that would lead to a real change, a clear break from the past, and fulfill the legitimate and democratic aspirations of the Syrian people," added the spokesman.