Syrian army threatens to encircle Aleppo as talks falter

Beirut: A Syrian military offensive backed by heavy Russian air strikes threatened to cut critical rebel supply lines into the northern city of Aleppo on Tuesday while the warring sides said peace talks had not started despite a U.N. statement they had.

U.N. envoy Staffan de Mistura announced the formal start on Monday of the first attempt in two years to negotiate an end to a war that has killed 250,000 people, caused a refugee crisis in the region and Europe and empowered Islamic State militants.

But both opposition and government representatives have since said the talks had not in fact begun and fighting on the ground raged on without constraint.

The opposition cancelled a meeting with de Mistura on Tuesday afternoon, and issued a statement condemning "a massive acceleration of Russian and regime military aggression on Aleppo and Homs", calling it a threat to the political process.

Rebels described the assault north of Aleppo as the most intense yet. One commander said opposition-held areas of the divided city were at risk of being encircled entirely by the government and allied militia, appealing to foreign states that back the rebels to send more weapons.

The main Syrian opposition council said after meeting de Mistura on Monday it had not and would not negotiate unless the government stopped bombarding civilian areas, lifted blockades on besieged towns and released detainees.

The head of the Syrian government delegation also denied talks had started after discussions with de Mistura on Tuesday.

Bashar al-Ja`afari said after two and a half hours of talks that the envoy had yet to provide an agenda or list of opposition participants. "The formalities are not yet ready," he told reporters at the United Nations office in Geneva.

He also said that if the opposition "really cared" about the lives of Syrians it should condemn the killing of more than 60 people on Sunday by Islamic State bombers in a neighbourhood that is home to the country`s holiest Shi`ite shrine.

A U.N. source said de Mistura had promised to present an opposition delegation list by Wednesday. Its makeup is subject to fierce disagreements among the regional and global powers that have been drawn into the conflict.

The refugee crisis and spread of the jihadist Islamic State through large areas of Syria, and from there to Iraq, has injected a new urgency to resolve the five-year-old Syria war.

But the chances of success, always very slim, appear to be receding ever more as the government, supported by Russian air strikes, advances against rebels, some of them U.S.-backed, in several parts of western Syria where the country`s main cities are located.