A “day of hope” had dawned, David Cameron insisted, after international leaders responded to his call for a greater response to the Syrian refugee crisis by pledging almost $11 billion or £7bn in humanitarian aid at a London conference.

Describing the gathering of leaders from some 70 countries as a “good and vital day's work," the Prime Minister said the extra funding would "save lives, will give hope, will give people the chance of a future".

Ban Ki-Moon, Secretary General of the United Nations, which was one of the co-hosts of the conference, hailed it as a "great success," saying: "Never has the international community raised so much money on a single day for a single crisis."

However, a similar pledge event last year promised to donate $7bn for the Syrian refugee crisis in 2015 but only delivered half that amount. Fears persist that some countries might have again over-promised.

Mr Cameron explained that £4.1bn or nearly $6bn had been pledged for this year alone with a further £3.4bn or almost $5bn to be handed over by 2020.

Britain is donating an extra £510 million for this year, taking the total funding from the UK to £2.3bn. An extra £1.2bn is being donated over the next four years.

The PM explained the money would help create one million jobs and a million school places for refugees in bordering countries.

"This is not just morally right; it is vital for long-term stability. We cannot have a generation of refugees left out of school, unable to get work, vulnerable to extremism and radicalisation," he said.

Among the other pledges for 2016 were $3.3bn from the EU, $2.6bn from Germany, $1bn from France and $925m from the US. Australia, Belgium, Italy, Poland, Japan, the United Arab Emirates, Austria, Switzerland, Estonia, Denmark and Finland also committed funds.

Countries in the region have agreed to open up their economies to create new jobs and the move will be further backed by £27bn of loans from international financial institutions and access to European markets.

"As a result there will be over one million new jobs in the region for refugees and residents alike," stressed Mr Cameron.

However, the upbeat nature of the aid conference was to a large extent overshadowed by the suspension of peace talks in Geneva and intense fighting on the ground in Syria. An Assad government offensive, backed by Russian air strikes, was continuing near Aleppo.

Ahmet Davutoglu, the Turkish Prime Minister, said an estimated 70,000 Syrians were fleeing the bombing and moving towards Turkey.

The PM insisted that the London conference had sent out a clear message to the people of Syria and the region: "We will stand with you and we will support you for as long as it takes to secure peace in Syria, to restore stability to the region and to give Syrian refugees a chance to go back and rebuild their homes and their country."