Turnbull warns of Syria 'proxy war'

Malcolm Turnbull has warned the conflict in Syria can't continue to develop into a proxy war.

Speaking on the sidelines of the United Nation's general assembly in New York, the prime minister said Australia supports any and every measure to aid peace and stability in Syria.

"I've spoken to many leaders in recent weeks about the Syrian situation and there is not a lot of optimism I regret to say. A political solution remains elusive."

Mr Turnbull said the situation is going to require a major step by the Russians to come together with the United States.

"This conflict in Syria cannot continue to develop into, in effect, a proxy war," he told reporters.

The prime minister discussed the importance of restoring the ceasefire with US President Barack Obama on Tuesday night (local time).

"It is vital for major players to reach resolution," he said, citing Russia, the US and the Gulf States.

Mr Turnbull warned the situation is much bleaker than it was a year ago when he spoke with world leaders.

The consequences of this war only get worse and worse, said.

"But often, as I say, it is darkest just before the dawn."

Foreign Minister Julie Bishop represented Australia at the International Syria Support group meeting on Tuesday morning (local time).

The sit-down, co-hosted by US Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov, came after the Syrian army declared an end to the week-long ceasefire.

It also follows significant air strikes in Aleppo and the bombing of an aid convoy carrying UN supplied food.