UN Secretary-General Ban Ki-moon on Tuesday called on states to stop sending weapons to the Syria conflict as the United States and Russia wrangled over destroying Syria's chemical weapons.

"I appeal to all states to stop fuelling the bloodshed and to end the arms flows to all parties," Ban said as he opened the annual UN General Assembly.

Russia is the key arms provider to President Bashar al-Assad while Syria accuses Saudi Arabia, Qatar and other Gulf states of arming opposition rebels.

The UN chief also called on Assad and the rebels -- and "all those in this hall with influence over them" -- to press for a peace conference to end the war that has left more than 100,000 dead.

"Military victory is an illusion. The only answer is a political settlement," he told world leaders.

Ban's appeal came as the United States and Russia haggled over a Security Council resolution to back an agreement for Assad to give up chemical weapons.

"I look forward to the imminent adoption of an enforceable Security Council resolution on chemical weapons," Ban said.

"This should be followed immediately by humanitarian action," he said.

US Secretary of State John Kerry was to meet his Russian counterpart Sergei Lavrov later in New York on Tuesday to discuss the UN resolution and their joint chemical disarmament plan.

A top Russian diplomat said that the resolution could be enforced under Chapter VII of the UN Charter.

Russia had earlier accused the United States and its allies of using "blackmail" at the United Nations by seeking approval for military force.

Ban voiced hope for progress in ending the 30-month civil war in Syria following the August 21 chemical attack near Damascus, which the United States estimates killed 1,400 people.

"The response to the heinous use of chemical weapons has created diplomatic momentum -- the first signs of unity in far too long," Ban said.

"Now we must build on it to get the parties to the negotiating table," he said.

Ban noted that "the vast majority" of the more than 100,000 dead in Syria were killed by conventional weapons.

"We can hardly be satisfied with destroying chemical weapons while the wider war is still destroying Syria," Ban said.

"It is time to end the killing and reach the peace the Syrian people need and deserve," he said.

US President Barack Obama and French President Francois Hollande had initially called for military action against Syria in response to the chemical attack, calling for accountability.

But the prospect of intervention was unpopular among Western publics in the wake of the Iraq war, with Britain's parliament refusing to back the use of force and a number of US lawmakers urging a non-military response.

Ban called for "full accountability for serious international crimes" -- either through the International Criminal Court in The Hague "or by other means consistent with international law."

Ban also returned to some of his key themes of encouraging development and fighting climate change.

The UN chief invited heads of state to a UN summit on climate change in September 2014 -- one year ahead of talks in Paris that have set the goal of a post-Kyoto Protocol treaty.

"The world's poorest and most vulnerable people, who are being harmed first and worst, are crying out for climate justice," Ban said.