David Cameron said Britain has spent over £300 million and "saved tens of thousands of lives" in Syria.
The Prime Minister said: "I've been to Jordan and seen one of the refugee camps myself and I know how much money and how much effort is going in.
"Britain, as ever, is a world leader at helping those who need help, and the people of Syria are right up at the front of that right now."
More top news
Springwatch presenter Chris Packham describes his battle with depression as "great, hopeless vacuum".
A newly promoted police officer caused a sensation with local women on Facebook