The spokesperson, Ahmed Fawzi, said Staffan de Mistura intends to resume talks between warring parties by 25 February and earlier if possible and is trying to convince those with influence over either side to persuade them to come to the table and “stop the madness”.

During a regular bi-weekly press briefing yesterday, Fawzi said the world cannot delay as the situation on the ground deteriorates, and that all parties had to fulfil the commitments necessary to progress.

Last Friday the International Syria Support Group, comprised of the UK, US, Germany, Russia, Iran and Saudi Arabia, but neither representatives of Bashar al-Assad or the Syrian opposition, agreed that a ceasefire should be secured within one week.

However, diplomats noted that the success of the agreement hinged on whether parties to the conflict agreed to and honoured its terms.

UK foreign secretary Phillip Hammond warned that Russian airstrikes in particular were a threat to the fragile agreement, but since its announcement the bombing campaign has continued.

The ISSG also agreed to begin the sustained delivery of humanitarian aid immediately, and today aid convoys have been loaded with food and medicine in preparation to head off to seven besieged locations in the war-torn country.

The convoys, announced by de Mistura last night, are expected to transport supplies to the starving residents of Madaya and Zabadani, under a siege by forces loyal to Assad, and simultaneously to Fua and Kefraya, besieged by rebel forces.

Convoys will also be sent to the Damascus suburbs of Moadamiyah and Kafr Batna in Ghouta, also besieged by the regime, and UN officials will meet today to decide whether to airdrop supplies into Deir ez-Zor, besieged by ISIS.