US threatens to end Syria talks with Russia

The US has warned that it could end talks with Russia on the Syrian conflict unless Moscow ends its bombing of rebel-held eastern Aleppo.

US Secretary of State John Kerry phoned his Russian counterpart on Wednesday to deliver the ultimatum after two hospitals were bombed in the morning by suspected Russian war planes.

"He informed the foreign minister (Lavrov) that the United States is making preparations to suspend US-Russia bilateral engagement on Syria ... unless Russia takes immediate steps to end the assault on Aleppo and restore the cessation of hostilities," state department spokesman John Kirby said in a statement.

During the conversation between Kerry and Lavrov, the US secretary of state is said to have expressed particular objections to the use of incendiary bombs in urban civilian areas.

Kerry's warning came after a week of massive bombing left over 300 Syrians in opposition areas dead and two hospitals in East Aleppo were targeted by airstrikes.

"Let us be clear. Those using ever more destructive weapons know exactly what they are doing," UN Secretary-General Ban Ki-moon

UN Secretary-General Ban Ki-moon has since condemned attacks on medical facilities in Syria.

He warned those behind the attacks "are committing war crimes", echoing previous statements by French, US, and UK officials.

"Let us be clear. Those using ever more destructive weapons know exactly what they are doing," Moon told a meeting of the UN Security Council.

"Imagine the destruction. People with limbs blown off. Children in terrible pain with no relief... Imagine a slaughterhouse. This is worse."

Targetting of medical facilities

In May, the UN Security Council adopted a resolution aimed at ensuring the protection of health workers and facilities operating in conflict zones.

However, there has since been little let-up on attacks targeting medical facilities in both Syria and Yemen.

Since the collapse of a US-Russian brokered ceasefire in Syria collapsed on 19 September, forces loyal to the Syrian regime have embarked on a new offensive on rebel-held Aleppo.

Activists in the city had reported the use of munitions including cluster, bunker-busting bombs, and even white phosphorus in recent attacks on populated areas in Aleppo.

Intense bombardments of residential districts by Syrian and Russian warplanes have also been accompanied by advances on the ground.

The Syrian army said on Tuesday that it had seized the rebel-held district of Farafira, located north-west of Aleppo's historic citadel.

It comes a week after the Syrian regime said it planned to retake all of the divided city.