The last doctors in the rebel-held east of the Syrian city of Aleppo have urged US President Barack Obama to come to the aid of the 250,000 civilians there.

A letter signed by 15 physicians warns that if attacks on medical facilities continue at their present rate, there could be none left within a month.

The Victoria Derbyshire programme's Jim Reed spoke to a doctor who signed the letter and a medic from Chicago who recently left the war-torn city.