US and Russia could 'start Third World War over Syria conflict', says Turkey

'If this proxy war continues, let me be clear, America and Russia will come to a point of war'

Syrian Civil Defence workers search through the rubble in rebel-held eastern Aleppo, Syria (AP)

The US and Russia could drive the world into a global war if the conflict in Syria is not resolved, Turkey has warned.

Tensions have become increasingly heightened between Washington and Moscow in recent weeks. Last week, the US and UK warned Russia and its ally the Syrian government that new economic sanctions could be imposed if the bombing of Syria's besieged Aleppo continues.

On Sunday, Russia condemned Washington for making “unprecedented” threats of cyber attacks following accusations by the Obama administration that Moscow had hacked computers belonging to American political organisations.

Turkish deputy prime minister Numan Kurtulmus said: "If this proxy war continues, after this, let me be clear, America and Russia will come to a point of war," the Daily Mail reports.

He suggested the Syrian conflict could be the beginning of World War Three, saying it had put the world "on the brink of the beginning of a large regional or global war".

Earlier this month a Russian newspaper warned that Russian President Vladimir Putin is playing an "astonishingly risky game" in the Syrian conflict that could lead to a Third World War.

Popular tabloid, Moskovsky Komsomolets, ran an article that suggested hostilities in Syria could spark a “direct military confrontation" between the nations of a similar scale to the 1962 Cuban Missile Crisis.

Russia's military announced on Monday that Russian and Syrian forces would halt hostilities for eight hours in the eastern districts of Aleppo.

It did not include any promises of an extended cease-fire and followed a bloody day of air strikes on rebel-held districts in and around the city.

The Britain-based Syrian Observatory for Human Rights said at least 50 civilians, including 18 children, were killed in air strikes on the eastern part of the city in the 24 hours before the Russian announcement.

Monday's air strikes coincided with the launch in neighbouring Iraq of a major operation by Iraqi and Kurdish forces, backed by the US-led coalition, to retake the northern city of Mosul from the so-called Islamic State group.

Mr Kurtulmus announced on Monday that Turkey is ready for hundreds of thousands of refugees from Mosul if the operations fuels sectarian violence.

"If the Mosul operation is handled correctly, there won't be a refugee wave into Turkey," Mr Kurtulmus told a news conference in Ankara.

"[But] if something goes wrong in Mosul, hundreds of thousands will put their migrant bags on their backs, they will be miserable and worn out, and come with their belongings to the only place they can go to, which is Turkey," he said.

The United Nations refugee agency said up to 100,000 Iraqis may flee to Syria and Turkey to escape the assault on Mosul, a city of 1.5 million people where Isis have declared a "caliphate".

Turkey is home to more than three million Syrian refugees, however its refugee camps can only house around 200,000 people.

Additional reporting by agencies