Syria government 'cuts off rebel-held Aleppo, renewing siege'

Syrian government troops on Sunday seized a military academy south of Aleppo city, once again encircling the rebel-held districts in the east and placing them under siege, a monitor said.

The Syrian Observatory for Human Rights, a Britain-based monitor, said government forces backed by Syrian and Russian air strikes had now severed the alternate route into the rebel east that opposition forces opened up in August.

"The army took control of the artillery academy, so they control all the academies, and the eastern neighbourhoods are under a full siege," said Observatory director Rami Abdel Rahman. 

There was no immediate confirmation in state media.

Government forces had been advancing in southern Aleppo for days, with the fighting already creating shortages for the estimated 250,000 people living in the rebel-held parts of the city.

But the capture of the academies, which straddle the road running to the eastern neighbourhoods, reinstates the government's encirclement of Aleppo.

Once Syria's economic powerhouse, Aleppo has been ravaged by the war that began with protests against President Bashar al-Assad's government in March 2011.

It has been roughly divided between rebel control in the east and government control in the west since mid-2012, and in recent months government troops have gradually surrounded the city.

On 17 July, they severed the only remaining route into the rebel-held east, the key Castello Road running down from the border with Turkey.

The road's capture led to shortages of food and fuel in the eastern neighbourhoods, and prompted international concern, including calls for 48-hour ceasefires to allow aid to enter.

On 6 August, rebel forces including al-Qaeda's former Syrian affiliate pushed government forces back from a key route south of the city, creating a lifeline back into the east.

While the reopening of the road allowed some goods into the city, it was inaccessible to most aid agencies, and negotiations to secure a route in for assistance have yet to succeed.

Russian backtracking

The US said on Sunday it had not yet struck a hoped-for deal with Russia on stemming the violence in Syria's brutal civil war, blaming Moscow for backtracking on issues it thought were settled.

President Barack Obama said earlier that the two sides were "working around the clock" on the sidelines of a summit in China, but that it was "a very complicated piece of business".

The State Department said a deal was close and could be announced by Secretary of State John Kerry and his Russian counterpart Sergei Lavrov, but hours later admitted defeat for now.

"Russians walked back on some of the areas we thought we were agreed on, so we are going back to capitals to consult," a senior State Department official said. 

Kerry and Lavrov will meet again on Monday in Hangzhou, where G20 leaders are gathered, he added.

Moscow and Washington support opposite sides in the Syrian conflict, which erupted in March 2011 after President Bashar al-Assad unleashed a brutal crackdown against a pro-democracy revolt. 

Successive rounds of international negotiations have failed to end a five-year conflict that has left more than 400,000 people dead and forced millions to flee, a key contributor to migrant flows into Europe.

Russia is one of Assad's most important international backers while the US supports Syria's main opposition alliance and some rebels, with other countries and forces also involved.

"Trying to corral all of those different forces into a coherent structure for negotiations is difficult," Obama said Sunday. "But our conversations with the Russians are key."

Fears for Aleppo

The US and Russia co-chair a UN-backed humanitarian taskforce for Syria, which has been struggling to ensure access for desperately needed aid across the country. 

The talks in Hangzhou are the latest round of diplomacy on Syria, after marathon negotiations between Kerry and Lavrov in Geneva last week failed to yield a final deal.

Kerry then listed two main priorities to ensure any new ceasefire holds: responding to violations by the Damascus government and checking the rising influence of the former al-Nusra Front.

That group has renamed itself Fateh al-Sham Front after renouncing its status as al-Qaeda's Syrian affiliate, but Kerry stressed that "Nusra is al-Qaeda, and no name change by Nusra hides what Nusra really is and what it tries to do".

Earlier truces have rapidly deteriorated, and Obama warned Sunday that the US was approaching the talks "with some scepticism".

"But it is worth trying," he said. 

"To the extent that there are children and women and innocent civilians who can get food and medical supplies and get some relief from the constant terror of bombings, that's worth the effort."