Kofi Annan, the United Nations and Arab League envoy to Syria, said Monday there can be no deadline for ending the Syrian crisis but it's urgent to move ahead quickly to stop the killing.
Annan told reporters before leaving Moscow for Beijing that above all, the Syrian government and opposition must start a political process to resolve the yearlong conflict peacefully.
"This cannot be allowed to drag on indefinitely," he said. "I think it is urgent to move ahead ... but it is not practical to put out timetables and timelines when you haven't gotten an agreement from the parties."
Annan has been in Moscow since Saturday for talks on Syria with Russian President Dmitry Medvedev.
Russia is Syria's most important ally and while Moscow _ along with China _ has twice shielded Syria from U.N. sanctions, both countries are strongly supporting Annan's mission. Moscow has signaled growing impatience with Syrian President Bashar Assad, with Russian Foreign Minister Sergey Lavrov pointedly criticizing him for being too slow with reforms.
Annan has proposed a six-point plan to Assad to end the conflict and he said Russia's leaders indicated they will use their influence "to help me constructively."
Medvedev strongly backed Annan's plan, adding that his mission "may be the last chance for Syria to avoid a protracted bloody civil war."
Annan's spokesman, Ahmad Fawzi, said in a statement later Monday that the Syrian government has formally responded to Annan's plan, which has been unanimously endorsed by the U.N. Security Council in a nonbinding presidential statement.
"Mr. Annan is studying it and will respond very shortly," Fawzi said.
Annan said it will be up to the Syrians themselves to decide if Assad should step down.
"It may in the end come to that, but it's not up to me, it's up to the Syrians," said Annan, a former U.N. secretary-general. "Our effort is to help the Syrians come to the table and find the way out of all of this."
Annan said the message he wants to send out today "is that the transformational winds blowing today cannot be easily resisted, or cannot be resisted for long."
"The only way to deal with this is through reform, through change _ and change that respects democratic principles, individual dignity, the rule of law and human rights," he said.
Annan's proposals include a cease-fire first by the Syrian government, a daily two-hour halt to fighting to evacuate the injured and provide humanitarian aid, and inclusive Syrian-led political talks "to address the legitimate concerns of the Syrian people."
Russia and China twice vetoed European and U.S.-backed resolutions condemning Assad's crackdown on protesters, which would have been legally binding. They called the resolutions unbalanced, saying they only blamed the Syrian government and demanded an end to government attacks, not ones by the opposition.
Moscow also argued that the resolutions promoted regime change in Syria and expressed fear of outside intervention to support the rebels, as happened in Libya.
As part of his discussions with Syria, Annan said the possibility of a U.N. observer mission in Syria had been raised.
"It's not excluded that a U.N. observer force may go in to ensure that the parties honor and respect the commitments that they are going to make," Annan said.
"We hope that they would agree to cessation of hostilities very shortly, and if that happens we will have to be on the ground to monitor and ensure that all sides are respecting the agreement," he said.
Edith M. Lederer contributed to this report from the United Nations