The United States and Russia clashed over Syria at the UN Monday after Secretary General Ban Ki-moon urged the divided Security Council to speak with one voice and help the Mideast nation "pull back from the brink of a deeper catastrophe."

Washington and Moscow both called for an end to the bloody yearlong conflict — but on different terms, leaving in doubt prospects of breaking a deadlock in the council over a new resolution.

U.S. Secretary of State Hillary Rodham Clinton rejected any equivalence between the "premeditated murders" carried out by Syrian President Bashar al-Assad's "military machine" and the civilians under siege driven to self-defence.

Russia's Foreign Minister Sergey Lavrov said Syrian authorities "bear a huge share of responsibility" but insisted opposition fighters and extremists including al-Qaeda are also committing violent and terrorist acts.

Lavrov said if the priority is to immediately end any violence and provide humanitarian aid to the Syrian people "then at this stage we should not talk about who was the first to start, but rather discuss realistic and feasible approaches which would allow [us] to achieve the ceasefire as a priority."

Security Council cannot 'stand silent,' Clinton says

Clinton declared that the Security Council cannot "stand silent when governments massacre their own people, threatening regional peace and security in the process."

The ministerial debate in the council on challenges from last year's Arab Spring was dominated by the conflict in Syria, which has killed over 7,500 people, according to the United Nations. On Monday alone, Syrian activists say that pro-government gunmen killed at least 16 people, including some children, in a rebel stronghold recaptured by the government.

Ban, who led off the debate, said the conflict has led the entire region into uncertainty and subjected citizens in several cities to disproportionate violence.

Russia, which is Syria's most powerful ally, and China have vetoed two U.S. and European-backed Security Council resolutions that would have condemned Assad's bloody crackdown, saying they were unbalanced and demanded that only the government stop attacks, not the opposition. Moscow accused Western powers of fuelling the conflict by backing the rebels.

Earlier this month, the United States proposed a new draft that tried to take a more balanced approach, but diplomats said Russia and China rejected it.

Lavrov flew to New York from Cairo, where he had a tense meeting with Arab League foreign ministers. They have endorsed a plan for Assad to hand power to his vice-president, but the Russians are adamantly opposed to any resolution endorsing regime change.

Agreement on plan for immediate ceasefire

In the end, the Arab League and Lavrov agreed on a plan that the Russia foreign minister said could lead to an early solution of the Syrian crisis: an immediate ceasefire, a clause preventing foreign intervention, assurances about humanitarian aid, an impartial monitoring mechanism and an endorsement of the mission by former UN chief Kofi Annan, the new UN-Arab League special envoy to Syria.

Annan left Syria on Sunday without a deal to end the conflict, while regime forces mounted a new assault on rebel strongholds in the north.

On Monday, Annan met Turkey's Prime Minister Recep Tayyip Erdogan in Ankara and told reporters the diplomatic process would take time.

"This a very complex situation," said Annan. "We are going to press ahead for humanitarian access, for the killings of civilians to stop, and that get everybody to the table to work out a political solution."

Clinton told reporters after meeting privately with Lavrov that she appreciated the opportunity to discuss the way forward and pointed out to him "my very strong view that the alternative to our unity on these points will be bloody internal conflict with dangerous consequences for the whole region."

She said everyone is waiting to hear Annan's advice on the best way forward, and the U.S. hopes that after Monday's council session and the recent meetings in Cairo and Damascus "we will be prepared in the Security Council to chart a way forward."

Lavrov said separate discussions with Clinton and the British and French foreign ministers "indicated that there is a growing understanding of the need not to talk to each other on the basis of take it or leave it, but to bring the positions together and to be guided not by the desire of revenge or punishment, who is to blame … but by the interests of the Syrian people."

Canada to give $6M more humanitarian aid to Syria

Also, on the sidelines of UN talks, the Quartet of Mideast peace mediators — the UN, U.S., European Union and Russia — met behind closed doors on the escalating Israeli-Palestinian conflict, which is witnessing the worst flare-up in violence in more than a year.

The ministerial meeting reviewed efforts to get the Palestinians and Israelis back to the negotiating table, but deep divisions remain and there is little hope of a breakthrough.

The Quartet expressed serious concern at the recent escalation in violence between Gaza and Israel and called for calm, and it again urged the Israelis and Palestinians to return to long-stalled negotiations and reach an agreement no later than the end of the year.

Meanwhile, Canada announced Monday another $6 million in emergency humanitarian assistance for Syria. Bev Oda, the minister of international co-operation, announced the extra funding, but did not reveal the identities of the specific agencies receiving the assistance for security reasons. The aid, given through the Canadian International Development Agency, will help provide access to emergency food assistance, safe water, sanitation facilities and other necessities to the victims of the ongoing violence.

"The violence in Syria is increasingly horrifying, causing death, injuries, and displacing thousands from their homes and communities. Canada remains very concerned for the people affected by this conflict," said Oda in a statement.  

With files from CBC News