Arab and western states will launch a fresh bid at the United Nations this week to put pressure on Syrian President Bashar al-Assad, setting off new diplomatic hostilities between Assad's friends and foes.
Saudi Arabia and Qatar have drawn up a resolution backing an Arab League plan to end the 11-month-old crackdown on protests which could be voted on at the UN General Assembly this week.
The move follows Russia and China's veto of virtually the same resolution in the UN Security Council eight days ago.
Russia and China are expected to oppose the new text but no one can veto resolutions in the 193-nation General Assembly, though they carry less weight.
Arab foreign ministers, meanwhile, on Sunday said they would open contacts with the Syrian opposition and called for a joint UN-Arab peacekeeping mission in the besieged country.
After a meeting in Cairo they also announced the end of a controversial Arab League observer mission sent to monitor violence in Syria, but which was pilloried for being toothless in the face of a 11-month crackdown on protests.
Syria rejected the latest moves by the Arab League.
In telephone talks with Arab League chief Nabil al-Arabi, UN Secretary General Ban Ki-moon "stressed that action on the specific requests of the League will be a matter for the Security Council to consider."
"The Secretary-General appreciates and commends the continued efforts of the League of Arab States to stop the violence in Syria and to seek a peaceful resolution of the crisis that meets the democratic and legitimate aspirations of the Syrian people," Ban said, according to his spokesman Martin Nesirky.
The new battle at the United Nations will see UN human rights chief Navi Pillay brief the General Assembly on Monday about Syria. The meeting was called by assembly president Nassir Abdulaziz Al-Nasser, who is from Qatar.
Pillay is no longer keeping a count of the dead in Syria as she says accurate information is unobtainable. Syrian activist groups say more than 6,000 have died since protests erupted last March.
The draft resolution "fully supports" the plan for Syria agreed by the Arab League last month, calling for Assad to transfer powers to a deputy so that elections can be held.
It condemns violence by all sides in Syria but specifically calls on Assad's government "to immediately put an end to all human rights violations and attacks against civilians."
China and Russia vetoed the UN Security Council resolution on February 4 because they said it was "unbalanced". Russia, in particular, has opposed any move that would force Assad, a key Moscow ally, to stand down.
Russia has maintained its stance. Deputy Foreign Minister Sergei Ryabkov said Friday that Moscow was ready to follow the Security Council veto with additional "strong measures" should the West continue to refuse to acknowledge the Syrian opposition's role in the crisis.
The United Nations leadership is also maintaining its tough stand, with Ban repeatedly calling on the government in Damascus to end the violence.
Ban "urges all in Syria and in the international community to exert maximum efforts to help bring about a stop to the violence and a peaceful resolution to the crisis," according to Sunday's statement from his spokesman.
"All violence must stop. The Secretary-General once again calls on the Syrian government to comply with international law and immediately end the shelling and use of force against civilians."
Two of Ban's key human rights advisors have again warned Assad that his "systematic attacks against civilians could constitute crimes against humanity."
Francis Deng and Edward Luck, the secretary general's special advisors on prevention of genocide and the protection of civilians, said they are "alarmed" by accounts of the government shelling of Homs and other cities.
The advisors said that even the government's claims that it is fighting armed groups could not be used as an excuse to fire on civilians.
"They underscore that both state and non-state actors have a responsibility to protect populations and can be held accountable for inciting or committing atrocity crimes," Deng and Luck said in a statement.
The pair said they were also "gravely concerned" by growing tensions among sectarian communities in Syria.