Arab and Western states urged the U.N. Security Council to act swiftly on a resolution calling for Syrian President Bashar al-Assad to step aside as his forces reasserted control of Damascus suburbs on Tuesday after beating back rebels at the gates of the capital.

The comments appeared designed to confront Russia over its reluctance to support the resolution and condemn Assad's government for its violent suppression of the protests. Moscow's U.N. envoy, however, said consensus was necessary and possible.

Arab League Secretary-General Nabil Elaraby asked the council for rapid and decisive action on a resolution to endorse the league's demand that Assad delegate powers to his deputy and defuse the 10-month uprising against his family's dynastic rule.

Qatari Prime Minister Sheikh Hamad bin Jassim warned the 15-nation body that Syria's killing machine is still at work.

Syria's U.N. Ambassador Bashar Ja'afari hit back, telling the council Arab League leaders had put a negative spin on a report by the League's monitors in Syria.

He sparred verbally with Sheikh Hamad, whose country has harshly criticized Syria and last year backed Western action in Libya that helped rebels take power. Is Qatar a member of NATO or the Arab League? Ja'afari asked with heavy sarcasm.

U.S. Secretary of State Hillary Clinton strongly backed the Arab League call for rapid Security Council action and warned that the violence was pushing Syria to the brink of civil war.

We all have a choice: stand with the people of Syria and the region or become complicit in the continuing violence there, she told the council, adding that the violence was increasingly likely to spiral out of control.

At the same time, Arab and Western nations attempted to allay Russian fears by making clear they were trying to avoid a Libyan-style foreign role in the Syrian crisis.

We are not calling for a military intervention, Sheikh Hamad said. We are advocating the exertion of concrete economic pressure so that the Syrian regime might realize that it is imperative to meet the demands of its people.

British Foreign Secretary William Hague told the council the resolution does not call for military action and could not be used to authorize it. French Foreign Minister Alain Juppe described the idea of such intervention as a myth.

The fate of the resolution depends on whether Russia, one of Assad's few remaining allies, can be persuaded not to veto the European-Arab draft resolution as Moscow and Beijing did to a European text in October that would have condemned Damascus and threatened it with sanctions.

Russian U.N. envoy Vitaly Churkin criticized the Arab League plan but said the inclusion of some of Russia's ideas in the draft resolution was a positive sign.

We found some of the elements of our text in it, and this gives rise for hope, Churkin said, referring to an earlier Russian draft resolution on Syria that had been rejected by Western powers and the Arab League as too weak.

We hope that the council will come to consensus on the Syrian issue, as is not only possible but also necessary.

Diplomats have been haggling for days to find a text Moscow will not block, with a main sticking point being the degree to which it expresses support for the Arab plan for Assad to give up powers, U.N. diplomats said.

BATTLEFRONT

On the battlefront, activists in eastern districts of Damascus said troops fired in the air as they advanced beyond areas from which the defector Free Syrian Army withdrew, capping three days of fighting activists said had killed at least 100 people. Tanks also swarmed into the area.

The suburbs are under an unannounced curfew. A small grocery shop opened this morning and soldiers came and beat the owner and forced him to shut down, said an activist in the Ain Tarma neighbourhood.

Others said residents of some eastern districts were allowed by advancing troops to flee their neighbourhoods, but security forces in the district of Irbin had rounded up young men at gunpoint and detained them.

Events on the ground are difficult to confirm as the Syrian government restricts most access by journalists.

Activist groups said 25 people were killed on Monday in Damascus suburbs and dozens more died in other parts of the country, mostly in raids in and around the central city of Homs, which has seen some of the heaviest attacks by Assad's forces.

The uprising against Assad - one of the most violent revolts of the Arab Spring - has entered a new phase in recent weeks, with an insurgency whose leadership is based in Turkey daring to show its face at the outskirts of the capital.

A last-ditch bid by Moscow to broker talks between Assad's government and rebels foundered when the opposition refused to attend, citing the continued killing, torture and imprisonment of the president's opponents.

Washington says countries need to accept that Assad's rule is doomed and stop shielding him in the Security Council.

I do not see how he can sustain his rule of Syria, U.S. Director of National Intelligence James Clapper said on Tuesday.

One of Russia's leading defence and security think-tanks, CAST, said Moscow could lose billions of dollars in military contracts with Assad if he is pushed aside.

A draft of the U.N. Security Council resolution obtained by Reuters emphasizes the need to resolve the current crisis in Syria peacefully. It does not authorize the use of force against Assad, though it includes a vague warning of possible further measures in the event of Syrian non-compliance.

U.N. Secretary-General Ban Ki-moon called for consensus among the council to stop the bloodshed, saying: Every day tens of people are killed ... It is crucially important for the Security Council to act on this.

Assad's forces appear to have decisively beaten back an attempt by the opposition to assert themselves near Damascus.

An activist said armed defectors mounted scattered attacks on government troops who advanced through the district of Saqba, held by rebels days earlier.

Rebel forays near the capital follow a negotiated victory in Zabadani - a town of 40,000 in mountains near the border with Lebanon - where government forces pulled back under a ceasefire.

Some rebel commanders have spoken of creating liberated territories to force diplomatic action.

Armour-backed troops entered al-Adawiya district in Homs, driving out Free Syrian Army rebels. Residents said tank bombardments and gunfire could be heard across the city in one of the heaviest barrages in weeks. Activists reported dozens of casualties and field hospitals full of wounded.

(Additional reporting by Suleiman al-Khalidi and Steve Gutterman; Writing by Patrick Worsnip and Joseph Logan. Editing by Christopher Wilson and Peter Graff)