The situation in Syria would have gone from bad to worse if Nato had intervened, according to the alliance’s head, Jens Stoltenberg. He warned of the dangers of military escalation in warzones such as Syria.

One the same day the UN Security Council planned to meet to discuss the worsening crisis in the city of Aleppo, Stoltenberg told the German newspaper Bild am Sonntag that a military mission in the country, which has been embroiled in an increasingly brutal civil war for more than six years, could have made an already bad situation worse.

“Sometimes it’s right to use military means – such as in Afghanistan. But sometimes the costs of military missions are greater than their benefits,” he said. “If every problem, every humanitarian catastrophe were answered with military force, we would end up in a world with even more war and suffering,” he said.

Meanwhile, Deutsche Welle (DW), Germany’s international broadcaster, quoted German Defence Minister Ursula von der Leyen has saying: “Neither the Syrian people nor the international community will forget the merciliness of [their actions in] Aleppo, which is unjustifiable. Whoever is responsible for the deployment of poison gas and bombs on hospitals and children can’t simply go back to normal.”

According to the Reuters news agency, the UN Security Council agreed on a French draft resolution aimed at ensuring that UN officials can monitor evacuations from the Syrian city of Aleppo. They were slated to vote on the text on December 18.

But DW noted that Russia’s UN Ambassador Vitaly Churkin said he would examine the draft. It was unclear whether the council would pass it.

According to the UN, some 40,000 civilians and rebels remain trapped in opposition-held parts of Aleppo, which recently has seen some of the worst violence of the entire war.

In a separate report, Turkey’s Anadolu news agency noted Syria has been locked in a vicious civil war since early 2011, when the Bashar al-Assad regime cracked down on pro-democracy protests – which erupted as part of the “Arab Spring” uprisings.

More than a quarter of a million people have been killed and more than 10m displaced across the war-battered country, according to the UN.