Syrian President Bashar al-Assad has promised that he would surrender Syria's chemical weapons but warned that disposal would take at least a year and could cost up to a billion dollars.

In a confident interview with a US TV network, President Assad reiterated his pledge to co-operate but warned against unrealistic expectations.

"I think it's a very complicated operation, technically.

"And it needs a lot of money, about a billion," he said.

"So it depends, you have to ask the experts what they mean by quickly.

"It needs a year or maybe a little bit more."

Mr Assad insisted that Syria was a victim of terrorism.

"What we have is not civil war. It's a new kind of war," he said, pointing out that Islamist guerillas from more than 80 countries had joined the fight.

The Syrian president admitted that at the start there had been non-jihadist rebels, but said that Islamist extremists had become a majority.

He added that "tens of thousands of Syrians" and 15,000 government troops had been killed "mainly because of the terrorist attacks and suicide bombers."

He also repeated his protestations of innocence over chemical attacks during the war.

Meanwhile, the five UN security council nations held talks on a resolution backing the Russian arms surrender plan.

UN envoys from the US, Russia, France, Britain and China held two hours of talks at the US mission.

"There is no accord yet, there will be more negotiations," said one UN diplomat.