The European Union on Thursday urged an "immediate halt" to fighting in the Syrian city of Aleppo to allow medical and humanitarian aid to reach an estimated 1.5 million trapped civilians.

"The EU and its member States call for... an immediate halt to the fighting in Aleppo to allow medical evacuations, deliveries of aid and repairing of essential water and electricity infrastructure," EU foreign affairs head Federica Mogherini said in a statement.