The PM outlined UK efforts to alleviate the humanitarian suffering in Syria and neighbouring countries and made clear the urgency behind finding a political solution to bring an end to the conflict.
Humanitarian response
On the on-going humanitarian crisis the PM said: "This is the refugee crisis of our time. A Syrian becomes a refugee every 15 seconds, that's 240 fleeing during the hour of this statement alone".
A Syrian refugee woman holds her child in Jordan's Za'atari camp. Photo: UNHCR/Sarah Malkawi
He added: "Britain is leading the world" in the humanitarian response and "will continue to shape more urgent, effective and large-scale humanitarian efforts".
At the summit the Prime Minister organised a special meeting, where agreement was reached to work through the UN to call for:
• safe, unimpeded access for humanitarian workers and aid convoys inside Syria
• help to deal with the impact of chemical weapons, including medicines and decontamination tents
• the world to make up the financial shortfall for humanitarian aid by the time the UN Assembly meets later this month
The PM also secured further aid commitments from several leading donor countries worth £164 million.
The UK government will keep up these efforts in the weeks ahead.
Read the full statement: G20 Summit: Prime Minister statement to the House of Commons
Read the latest news on the government's response following the Syria chemical weapons attack.
Key facts
According to the UN High Commissioner for Refugees, there are:
• 6.8 million people in need of humanitarian assistance in Syria
• 4.25 million refugees in Syria
• 2 million Syrian refugees in neighbouring countries
How the UK is helping
The Prime Minister announced last week that the UK will provide £52 million in new humanitarian funding. This brings the UK's total funding to £400 million, double the £200 million of the UK's largest previous response to a humanitarian crisis.
The aid will give support including food, medical care and relief items for over a million people, the majority of who are women and children, who have been affected by the fighting in Syria and to refugees in Lebanon, Jordan, Turkey and Iraq.
Read how the UK is responding to the humanitarian crisis - Syria crisis: latest updates on UK aid and visit the Syria crisis: UK aid response page on Facebook.
Video: See how UK aid is helping Syrians who have fled the fighting.
How you can help
The best way to help those hit by the crisis is to donate to the Disasters Emergency Committee (DEC) Syria Crisis Appeal.