International Development Secretary Justine Greening has pledged the UK will provide an extra £21 million in aid for those affected by the conflict in Syria.
Ms Greening was visiting the Za'atri refugee camp in neighbouring Jordan, where the flow of people fleeing the war zone has been described by the United Nations (UN) as "absolutely dramatic".
It means the UK has now provided a total of £89.5 million in aid for those caught up in the Syrian civil war between forces loyal to Syrian president Bashar al-Assad and those who oppose him.
Ms Greening said: "My visit today has given me the chance to see first-hand the incredible generosity of spirit that ordinary Jordanians have shown in opening their homes to complete strangers in need.
"It is a story repeated in towns and villages in Syria's neighbours across the region, and I salute these ongoing efforts from governments and host communities alike.
"But we cannot and must not leave them to shoulder this response alone.
"This is a man-made crisis. That man is Assad."
Half of the new tranch of aid (£10 million) will be used to help Jordan deal with the influx of refugees.
According to the UN, about 6,400 Syrians have arrived at the main refugee camp in Jordan in the last 24 hours alone.
The remaining funds will be used to restock medical facilities and treat tens of thousands of injured and sick people inside Syria.
It will also be used to buy vital supplies of bread and flour and winter clothing.
Aiming to reach people in both loyalist and opposition-held areas who have been hit by the fighting and food and fuel shortages, it will be channelled through aid agencies.
Ms Greening called on other members of the international community to shoulder more of the burden for providing aid ahead of a donor's conference in Kuwait next week.
She said: "The UK and a handful of others have consistently led the way in responding to this crisis.
"But while a small number are doing a lot, the vast majority are still not doing enough.
"This is simply not acceptable and it has to change."
David Cameron visited the Za'atri camp in November and vowed to work with US president Barack Obama to find ways to end the bloodshed in Syria after hearing "horrendous" stories of suffering from refugees.
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The Prime Minister said: "I wanted to hear for myself the stories of people who have been bombed and shot and blasted out of their homes in Syria by a deeply-illegitimate and unpleasant regime that is raining down death and destruction on its own people."
Since the conflict started in Spring 2011, some 60,000 Syrians have been killed, four million are in need and more than two million have been internally displaced.
