Syrian president Bashar al Assad has said a victory in Aleppo would be "a very important springboard" to pushing "terrorists" back to Turkey.

Mr Assad said Aleppo is effectively no longer Syria's industrial capital - but taking back the city would provide important political and strategic gains for his regime.

He told Russian newspaper Komsomolskaya Pravda: "It's going to be the springboard, as a big city, to move to other areas, to liberate other areas from the terrorists. This is the importance of Aleppo now.

"You have to keep cleaning this area and to push the terrorists to Turkey to go back to where they come from, or to kill them. There's no other option. But Aleppo is going to be a very important springboard to do this move."

Syrian government forces have encircled eastern Aleppo, besieging more than a quarter of a million people who they say are being used as human shields by "terrorists".

Rescue workers said that Syria's military backed by Russian warplanes had killed more than 150 people in eastern Aleppo this week, in support of its offensive against the city.

The siege has caused an international outcry with a number of countries and groups accusing Syria and Russia of war crimes in connection with attacks on medical facilities and aid convoys.

Syria's civil war, now in its sixth year, has killed 300,000 people and left millions homeless.

'More than Cold War'

President Assad is backed by the Russian air force, Iran's Revolutionary Guards and an array of Shi'ite militias from Arab neighbours.

Sunni rebels seeking to oust him are backed by Turkey, the United States and Gulf monarchies.

Mr Assad also told the newspaper that the country's civil war had become a conflict between Russia and the West.

"What we've been seeing recently during the last few weeks, and maybe few months, is something like more than Cold War," he said.

"I don't know what to call it, but it's not something that has existed recently, because I don't think that the West and especially the United States has stopped their Cold War, even after the collapse of the Soviet Union."

Mr Assad added that Turkey's actions in Syria constituted an "invasion, against international law, against the morals, against the sovereignty of Syria".

Meanwhile, a car bomb near the Syria Turkey border crossing close to the city of Azaz has killed at least 20 people.

The blast reportedly took place near a checkpoint manned by a group of Free Syrian Army's Jabhat al Shamiya.