The Arab League called Sunday for the creation of a joint Arab-United Nations peacekeeping mission to halt the escalating violence in Syria, as Syrian government forces sustained their assault against protest strongholds in the city of Homs and elsewhere.

Syria immediately rejected the resolution, adopted at a meeting of Arab League foreign ministers in Cairo, and with Russia still firmly opposed to U.N. action against Syria, it seemed unlikely such a mission would be formed anytime soon.

The Arab League also ended its monitoring mission, which was suspended earlier this month after it was widely condemned as ineffectual and because it was becoming too dangerous for the monitors.

But Sunday’s appeal indicated the increasing frustration of at least some Arab states with the world’s failure to take action to stem the bloodshed. Saudi Arabia’s foreign minister, Prince Saud al-Faisal, told those at the meeting that “the Syrian leadership has chosen chaos, and is killing people and destroying the nation only to maintain its authority.”

The Arab League asked member states to provide “all forms of political and financial support” to the Syrian opposition and to cease “diplomatic cooperation” with the Syrian regime. But the resolution stopped short of recognizing the Syrian National Council, the main opposition group, as the legitimate representative of Syria, which had been proposed by some states before the meeting.

The resolution did not spell out exactly what the mission of the proposed U.N.-Arab force would be, and Security Council diplomats in New York said they were still unclear about the specifics of the request. U.N. Secretary General Ban Ki-moon last week urged the world body to contribute to an expanded form of the Arab observer mission, which was set up to monitor Syria’s compliance with a November cease-fire agreement that was never implemented.

The Syrian ambassador to Cairo, Youssef Ahmed, said the Arab resolution showed the “state of hysteria” within the Arab League after its failure to secure support for its peace plan at the United Nations this month.

The Russian and Chinese veto of the U.N. Security Council resolution has left the international community divided between those who support the Syrian uprising’s call for the ouster of President Bashar al-Assad, including the United States, Europe and most of the Arab states, and Syria’s allies who do not, including Russia, Iran and China.

The U.N. General Assembly plans a public debate Monday on Syria’s human rights conduct, featuring an address by the U.N. high commissioner for human rights, Navanethem Pillay. Arab governments plan to put forward a resolution condemning Syria and calling on U.N. members to endorse an Arab League plan calling for a transition to a national unity government in Syria.

In Syria, attacks on areas loyal to the Syrian opposition continued, although the intensity of the bombardments on the city of Homs appeared to have eased. The Local Coordination Committees said 23 people died Sunday across the country.

Also Sunday, al-Qaeda leader Ayman al-Zawahiri issued a videotaped message urging Muslims living in countries adjoining Syria to support the revolution there.

The message comes amid growing concerns that al-Qaeda influenced groups may be trying to muscle in to the increasingly chaotic situation in Syria. Three recent suicide bombings in Damascus and two in Aleppo may have been carried out by al-Qaeda operatives, U.S. officials say, although they add that there is no indication that the Syrian opposition is falling under the influence of extremist groups.

Zawahiri urged Syrians, many of whom have been calling for international military intervention, not to seek the assistance of the West or other Arab states. He also urged Muslims elsewhere to volunteer to help the Syrian uprising against Assad’s “sectarian and agent regime.”

“I appeal to every Muslim and every free, honorable one in Turkey, Iraq, Jordan and Lebanon, to rise to help his brothers in Syria with all what he can, with his life, money, wonders, opinion and in formation,” he said.

Staff writer Colum Lynch at the United Nations contributed to this report.