Syria's President Bashar al-Assad said on Friday that the Syrian army's capture of Aleppo, which has come under renewed bombardment in an effort to seize its rebel-held sector, would be "a very important springboard" to pushing "terrorists" back to Turkey.
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.
Rising casualties in Aleppo, where many buildings have been reduced to rubble or are lacking roofs or walls, have prompted an international outcry and a renewed diplomatic push, with talks between the United States and Russia planned for Saturday.
"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," Assad said in an interview with Russian tabloid Komsomolskaya Pravda.
"Aleppo is going to be a very important springboard to do this move," added Assad.
As the air strikes and shelling of the city's east intensified after a brief period of relative calm, Syria's government approved a United Nations plan to allow aid convoys into the most besieged areas of Syria, with the exception of Aleppo.
Syria's civil war, now in its sixth year, has killed 300,000 people and left millions homeless while dragging in regional and global powers as well as inspiring jihadist attacks abroad.
Assad is backed by the Russian air force, Iran's Revolutionary Guards and an array of Shi'ite militias from Arab neighbours, while Sunni rebels seeking to oust him are backed by Turkey, the United States and Gulf monarchies.
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," Assad 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."
Assad added that Turkey's actions in Syria constituted an "invasion, against international law, against the morals, against the sovereignty of Syria."
'May amount to war crimes'
As air strikes killed 13 people on Thursday in the rebel-held Aleppo districts of al-Kalaseh, Bustan al-Qasr and al-Sakhour, according to a civil defence official, European Union foreign ministers drafted a statement accusing Syria and its allies of violence that "may amount to war crimes."
"Since the beginning of the offensive by the (Syrian) regime and its allies, the intensity and scale of aerial bombardment of eastern Aleppo is clearly disproportionate," a draft of their statement seen by Reuters said.
Syrian and Russian governments say they target only militants.
To the south, hundreds of insurgents and their families have left two rebel-held towns on the northern outskirts of Damascus, residents and fighters said, under a deal with the government which is pushing its opponents to rebel areas further from the capital.
The evacuation happened after the army gave community leaders in Qudsiya and Al-Hama - which had enjoyed relative calm under local truces - an ultimatum to get several hundred fighters out of their towns or face a wide-scale assault.
"They gave us little option: Leave or all hell breaks loose," said Yousef al Hasnawi, a resident on the local rebel council.
The Damascus government says such amnesties are a "workable model to bring security and peace," but its opponents say forcing Sunni Muslim fighters and their families from their hometowns could create new demographic frontiers and worsen sectarian tensions.
Obama to review options
US President Barack Obama and his senior foreign policy advisers are expected to meet on Friday to consider military and other options in Syria, US officials told Reuters.
Some officials argue the United States must act more forcefully in Syria or risk losing what influence it still has over moderate rebels and its Arab, Kurdish and Turkish allies in the fight against Islamic State.
US officials said they considered it unlikely that Obama would order US air strikes on Syrian government targets, and stressed that he may not make any decisions at the planned meeting of his National Security Council.
US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov are due to meet in Switzerland on Saturday to resume their effort to find a diplomatic solution along with counterparts from some Middle Eastern countries.
Moscow called on Thursday on states in the region not to supply portable anti-aircraft missiles to Syrian rebel groups, warning that any unfriendly actions against Russian forces would draw an appropriate response.
'It's going on now'
Air strikes against rebel-held areas of eastern Aleppo had tapered off over the weekend after the Syrian army announced it would reduce raids for what it described as humanitarian reasons, but they have intensified since Tuesday.
"The bombing started at 2 amand it's going on until now," Ibrahim Abu Laith, an official at the civil defence rescue organisation in Aleppo, told Reuters from the city.
Rescue workers said 154 people had been killed in recent days. Reuters could not independently verify the death toll.
Aleppo has been divided between government- and rebel-controlled areas for years. More than 250,000 people are believed to be trapped in eastern Aleppo - the anti-Assad rebels' most important urban stronghold - facing shortages of food, fuel and medicine.
In Geneva, the United Nations said Damascus had partially approved its aid plan for October, giving the green light for convoys to 25 of 29 besieged and hard-to-reach areas across Syria, which are also deprived of some vital supplies.
But the Syrian government did not give approval for either eastern Aleppo or three districts near Damascus, Ramzy Ezzeldin Ramzy, the United Nations' deputy special envoy to Syria, said on Thursday, describing the situation as "dire."
In a government-held area of western Aleppo, at least four children were killed and 10 wounded on Thursday when shells landed near a school, the Syrian Observatory for Human Rights reported.
Syrian state news agency SANA said the school in the al-Suleimaniya area had been targeted in what it described as a terrorist attack.